Biorealism today-Lessons Learned from Richard Neutra's UCLA Lab School_reduced_SECURED

Research team:

Widya Ramadhani, PhD, EDAC, WELL AP, Design Researcher and Associate, Perkins Eastman

Emily Chmielewski, EDAC, Design Research Director and Senior Associate, Perkins Eastman

Heather Jauregui, AIA, LEED AP BD+C, O+M, CPHC, Director of Sustainability and Principal, Perkins Eastman

Megan Loef Franke, PhD, Professor, Education, University of California, Los Angeles

Christine Lee, PhD, CONNECT Research, University of California, Los Angeles

Sean O’Donnell, FAIA, LEED AP, K-12 Practice Area Leader and Principal, Perkins Eastman

Rebecca Milne, LEED Green Associate, Director of Design Strategy and Associate Principal, Perkins Eastman

With special thanks to: Raymond Neutra and the Neutra Institute for Survival Through Design; and Ruisheng Yang, Perkins Eastman 2022 Design and Wellness Fellow.

Design: Marisa Avelar

Graphics and Illustrations: Vyjayanthi Janakiraman, Widya Ramadhani

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EXECUTIVE SUMMARY

At the crossroads of climate disruption and pedagogical change, schools must be adaptive and resilient. UCLA Lab School, located on the University of California, Los Angeles campus, serves as a model of architectural and pedagogical innovation. Architecturally, UCLA Lab School, which integrates architecture and nature to support human health and well-being, is an important example of biorealism, a philosophy developed by mid-century modernist Richard Neutra. Pedagogically, the school is a leader in progressive education, thanks to the efforts of Principal Corrine A. Seeds, who was influenced by reformer John Dewey and advocated for a progressive education that is dynamic and grounded in children’s experiences and exploration. In 1950, Neutra and fellow architect Robert Alexander collaborated closely with Seeds to design an elementary school campus with strong connections to nature, flexible learning environments, and spaces that encouraged children’s movement and exploration.

UCLA Lab School offered a unique opportunity to study resiliency through the dual lenses of architecture and pedagogy—an intersection rarely explored in relation to indoor environmental quality (IEQ). Using a mixed-method approach combining digital modeling, climate projections, occupant surveys, classroom observations, and sensorbased measures of IEQ, we investigated the interrelationship between inquiry-based learning pedagogy, the indoor–outdoor environments in which it unfolds, and IEQ. This integrated perspective revealed how Neutra’s biorealistic design continues to foster flexible and comfortable settings that support inquiry-based learning amid changing climate conditions and evolving educational practices.

We discovered how design and behavior shape IEQ and perceived comfort in UCLA Lab School classrooms. In naturally ventilated classrooms, outdoor temperature shifts had a minimal impact on perceived thermal comfort, suggesting opportunities to enhance comfort through

passive design and occupant education on how to utilize the space without relying on mechanical systems. While surveys indicated better perceived thermal comfort in the school’s mechanically ventilated rooms, temperature data revealed little difference between naturally and mechanically ventilated spaces, suggesting that external factors influence perceived comfort. Air quality results further underscored this dynamic: mechanically ventilated classrooms saw elevated CO2 levels, likely due to reduced fresh air exchange when compared to naturally ventilated classrooms, which benefited from occupants opening windows and doors. We discovered that UCLA Lab School’s CO2 levels were lower than those in typical, mechanically ventilated schools—even in high-performing facilities. While the design’s natural ventilation strategies play a role in this finding, we identified a key factor contributing to improved indoor air quality for any space, which we are calling a “fresh-air break.” When occupants leave, the classroom’s CO2 levels do not continue to escalate throughout the day. As a result, CO2 levels can recover and restore air quality to healthier levels, which supports cognitive function. This illustrates how behavioral strategies can enhance IEQ, with additional recommendations available in the printable Guide for Teachers included in this report.

Our findings underscore the importance of collaboration among architects, educators, and researchers in addressing challenges and developing solutions that integrate architectural and pedagogical strategies for optimal learning. Lessons from UCLA Lab School position it for continued success; they also provide evidence-based approaches to extend the benefits of biorealism to other schools. For teachers, designers, and building operators, this report provides practical guidance on adapting both new and existing facilities to meet evolving needs, thereby fostering effective teaching and learning for generations to come.

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BIOREALISM AND PROGRESSIVE EDUCATION

Richard Neutra’s biorealistic design remains relevant today, providing adaptable, comfortable environments that support inquiry-based learning as the climate changes.

COMFORT BEYOND MECHANICAL SYSTEMS

Climate-appropriate passive design and behavioral strategies can keep classrooms comfortable without full reliance on a building’s mechanical systems.

FRESH-AIR BREAKS

Leaving classrooms empty for short periods helps to reduce CO2, improving air quality and supporting cognitive function.

Decrease Indoor CO2 Levels Enhance Learning Conditions Implement Fresh Air Breaks

INTRODUCTION

When architect Richard Neutra published Survival Through Design, he introduced the world to a new concept: biorealism, short for “biological realism,” which he defined as “the inherent and inseparable relationship between man and nature.”1 Much has changed in the 70 years since biorealism entered the lexicon. We are living in a time of global disruption, from pandemics that upset our community systems to climate change that devastates environments and cultures. People are paying greater attention to the built environment’s impact on individuals, communities, and the world. In light of current global challenges, Neutra’s assertion that design can play a critical role in human and environmental resilience remains strikingly relevant.

Note: The use of the word “man” in Richard Neutra’s writings reflects the language of his time. However, the reference in this report is not intended to denote male preference. Instead, the authors would write: Biorealism is the inherent and inseparable relationship between people and nature.

When it comes to school facilities, environmental impact is top of mind. During the COVID-19 pandemic, the importance of indoor-outdoor connections and fresh air for occupants of all building types garnered many headlines, and schools

were no exception.2 This visibility prompted many schools to initiate new strategies to increase fresh air circulation to indoor classrooms for resiliency purposes. However, additional affordances must be made when considering indoor-outdoor connections and other strategies in school environments. Within schools, there is a symbiotic relationship between inquiry-based learning pedagogy, indoor-outdoor learning spaces, and indoor-outdoor environmental quality that supports and enhances, rather than limits, education.

UCLA Lab School was built in 1958. It exemplifies the combination of progressive learning and abundant indooroutdoor connections. A product of principal Corrine A. Seeds’s dream of a building that inspires children’s curiosity and active learning and Neutra’s biorealism, the school has been referenced in a variety of research over the years. As a laboratory school, it is a testing ground for new ideas and an apt subject for an investigation into how school design and pedagogy can adapt to the changing climate. Lessons learned through our research position UCLA Lab School for future success and also provide documentation of the evaluation process, suggesting design approaches that other schools can use in developing their own site-specific, future-proofing strategies.

BIOREALISM

Biorealism encompasses Neutra’s belief that architecture should be in harmony with the natural world to promote human health and well-being. From Hippocrates to Freud, Neutra was influenced by advancements in areas such as psychology, neurology, and physiology—incorporating multiple disciplines into his architectural work.3 His approach went beyond aesthetics; his holistic philosophy linked people, the built environment, and nature.

Neutra’s biorealism centers on the design of healthy and livable buildings and communities. In this mindset, design is about more than high-performing buildings, such as those optimizing energy consumption, water use, and construction waste. Biorealistic designs support the health and well-being of people and the natural world. In this way, the concept of biorealism can be seen as a precursor to today’s definition of the triple bottom line in sustainability constructs, which take into consideration the interrelationship between planet, people, and profit.4

NEUTRA’S BIOREALISM

SUSTAINABILITY’S TRIPLE BOTTOM LINE

PEOPLE

PEOPLE

The concept of biorealism can be seen as a precursor to today’s definition of sustainability’s triple bottom line.

Biorealism encompasses Neutra’s belief that architecture should be in harmony with the natural world to promote human health and well-being

Neutra’s biorealistic designs rely on three main pillars: (1) integrating and blending in with natural surroundings; (2) designing for human minds, bodies, and behaviors; and (3) conserving resources and protecting the natural world. This framework is expressed through design features such as natural materials, open and flexible floor plans, large windows for views and daylighting, and access to fresh air. Outdoor spaces such as gardens and courtyards are also common in Neutra’s designs. The interrelationships of building, site, and natural surroundings are given equal weight within the concept of biorealism, and each one is considered a component of a balanced ecosystem.

Ahead of his time in this regard, Neutra recognized the role the built environment plays in the holistic well-being of people, communities, and the planet. His principles and applications of biorealism have commonalities with 21st century architectural principles and practices, including evidence-based design, neuroscience-driven design,

biophilia, and sustainability.5 Neutra believed that good architecture should be informed by human cognition and physiology—it should consider the ways humans process information and respond to the environment. He also believed that enhancing architecture’s connection to the natural world can help minimize its negative impact on the planet.

Neutra believed in the survival of humanity through design. Recognizing how poorly designed settings and certain manufactured materials were negatively impacting the health and wellness of people, he developed biorealistic design to create more livable environments. By applying the concept of biorealism to design today, we can shape healthier environments. We can use it to support building occupants and minimize negative ecological impacts to address our current challenges—climate change, urban population growth, increases in chronic diseases, and health implications of synthetic materials among them.

“THE ARCHITECT IS A PHYSIOTHERAPIST AND AN ECONOMIST; HE CAN CERTAINLY SUPPORT VITALITY AND HEALTH.

— RICHARD NEUTRA, BUILDING WITH NATURE

APPLYING NEUTRA’S BIOREALISM TODAY

PRIORITIZE HEALTH AND WELLNESS

Consider physiology, psychology, and behaviors in all design decisions.

REDUCE ENVIRONMENTAL IMPACT

Apply ecologically sustainable practices, technologies, and materials.

DESIGN FOR CLIMATE RESILIENCE

Respond to site’s climate and ecology, while planning for future shifts such as rising temperatures.

ALIGN DESIGN WITH NATURAL SYSTEMS

Select site and orientation that allow integration of natural elements, abundant daylight, and healthy indoor air quality.

STRENGTHEN HUMAN–NATURE CONNECTIONS

Provide access to outdoor views and spaces, dynamic light, biomorphic patterns, and natural materials.6

PROMOTE HEALTHY LIFESTYLES

Design spaces that encourage movement, physical activity, and engagement with nature.

ABOUT UCLA LAB SCHOOL

UCLA Lab School was established in 1882 as a demonstration school for the southern branch of the California State Normal School. Between 1914 and 1919, the expanding Normal School moved to a larger site on Vermont Avenue and became part of the Southern Branch of the University of California, which was renamed UCLA in 1927. In 1929, UCLA relocated to Westwood, and the demonstration school was renamed the University Elementary School (UES), with its bungalows relocated near Warner Avenue. Later, in 1949, UES was relocated to a new location on the UCLA campus, occupying a one-story building designed by architect Robert Alexander.7 Between 1957 and 1958, Neutra and Alexander collaborated on the design of three building additions to the campus: (1) a long, bar-shaped building; (2) a set of four classrooms clustered around a central hall; and (3) a series of three classrooms

UCLA LAB SCHOOL SITE PLAN

arranged in a “finger plan” fanning out from a curved corridor with courtyards in between.

Although the finger plan component was demolished in 1992, the remaining school buildings continue to preserve Neutra’s biorealism intent. Neutra and Alexander’s work for UCLA Lab School prioritizes natural ventilation and daylight and engages the surrounding landscape as a seamless extension of the indoor learning environment. The extant buildings, slightly separated on the site, are connected via a covered walkway. Each classroom has access to outdoor environments including a patio and outdoor workstation accessible through sliding doors. The classrooms are spaciously designed to accommodate student groups and observers.

UCLA Lab School is well integrated within the surrounding outdoor landscape, which acts as an extension of the indoor learning spaces. (UCLA Lab School c. 1958)

UCLA Lab School currently serves approximately 450 students, ages four to 12 in prekindergarten to grade 6. It upholds its laboratory school mission through its affiliation with UCLA’s School of Education and Information Studies and provides a place to conduct educational research. It is a testing ground for innovative teaching and learning methods, hosting researchers who design and study educational environments and practices. An inquirybased curriculum is at the heart of teaching and learning at the school. Rooted in curiosity, information gathering, problem-solving, and exploration of ideas, inquiry-based learning also centers on and honors children’s experiences, understanding, and cultural practices as an important and valuable part of classroom learning.

One of the ways UCLA Lab School leverages inquiry-based pedagogies is by considering the environment—indoors and out—as an important part of exploring and learning in the 21st-century. The children, faculty, and researchers at UCLA Lab School view the environment as a “third teacher,” alongside parents (the first teacher) and educators (the second teacher). Beyond the classroom, for example, students explore the rich learning environments, resources, and materials of the outdoors to spark investigations, questions, and interests—further encouraging physical activity and exploration in learning.

Inquiry-based learning is rooted in curiosity, research, problem-solving, and exploration of ideas It centers on and honors children’s experiences, understanding, and cultural practices as an important and valuable part of classroom learning This concept also furthers the importance of investigating how students and educators move about and engage within school environments

HOW UCLA LAB SCHOOL APPLIES NEUTRA’S BIOREALISM

UCLA Lab School is an exemplary site to investigate the impact of biorealism on the learning experience because it embodies an inquiry-based pedagogy within an ecosystem that bridges both the built and natural environments.

Integrating the building with the site’s natural surroundings.

Utilizing sliding glass doors to enable direct access to the outdoors and blur boundaries between indoor and outdoor learning.

Incorporating large expanses of glass to offer views of nature, maximize daylight, reduce reliance on electric lighting, and support circadian rhythms.

Using natural materials/finishes.

Enabling natural cross-ventilation to promote healthy indoor air quality.

Providing flexible furniture and spaces that meet diverse needs and support educational engagement.

Adding wide roof overhangs to provide shade and mitigate excessive heat gain and glare.

DRIVING FORCES: CLIMATE CHANGE AND TEACHING PEDAGOGIES

Changing climate conditions and progressive educational practices demand resilient, adaptable, and flexible school environments.

As climate change and environmental crises escalate, architects are shifting toward more sustainable practices. The built environment is responsible for approximately 42% of annual global carbon dioxide (CO2) emissions, encompassing both operational emissions from building use and embodied emissions from materials and construction.8 Within the field of architecture, sustainability encompasses a holistic approach to design—combining form, function, and efficiency to minimize impact on the planet. Whether designing new buildings or modifying existing structures, architects must conscientiously examine the environmental footprint of their work and implement sustainable design principles to mitigate their project’s adverse effects on local and global ecologies.

When designing schools to support 21st-century learning principles, in addition to pedagogy and curriculum, we must consider urbanization, climate change, health indicators, and infrastructure assessments, with an emphasis on flexibility, sustainability, and community engagement9

The field of education similarly strives to understand generative ways of teaching and learning for these modern times. Educators are urged to create authentic learning experiences that nurture and affirm children’s voices, ideas, and interests. It is important to consider sustainability alongside the critical engagement of children in educational environments within these teaching philosophies and pedagogies. Approaches that do so often incorporate the natural world into learning, which fosters active, rather than passive, participation. This puts a sharper focus on the importance of flexible and adaptable classroom spaces— prompting designers and educators alike to consider the diverse modes of learning and pedagogical approaches that allow for more than a student sitting in their chair listening to a lecture. Thus, as students are encouraged to move about and engage in their learning in nontraditional ways, the educational environment, inside and out, must enable opportunities for progressive educational practices.

Classroom comfort is another essential factor in supportive learning environments. Unfortunately, in the face of a rapidly warming global climate, a considerable number of US school administrators and facilities managers are struggling to maintain comfortable learning environments in older school buildings due to design and systems inadequacies.10 Poor environmental conditions are common in these outdated facilities, with nearly half of US schools reporting such issues.11 Furthermore, a school’s ability to provide healthy,

safe, and comfortable spaces is critical: the comfort of the learning environment affects student attendance, performance, and achievement.12 For this study, we defined comfort in school environments in two intersecting ways: (1) the indoor environmental quality (i.e., thermal comfort, acoustics, lighting, and air quality) and (2) classroom utilization for various pedagogies.

Comfortable temperatures, lighting, acoustics, and fresh air provide a conducive environment for students to learn and engage. Conversely, the way students are learning—and the associated classroom space utilization—can change the IEQ, such as louder noise levels, higher ambient temperatures, and increased CO2 levels. When conditions fall outside the comfort range, they can affect educational performance. For example, a 2017 study of 4.5 million New York City high school exit exams found that students taking a test on a 90°F day versus a 75°F day were 12.3% more likely to fail.13 Regulating thermal comfort in schools has also

been shown to reduce fatigue, irritability, and stress.14

To achieve thermal comfort, however, the conventional approach to school design relies heavily on energy-intensive mechanical systems for classroom spaces. But this approach contradicts fundamental goals for sustainable schools by wasting energy and funds. In fact, a study found that by addressing mechanical system issues, schools were able to cut annual energy expenses by 12%—equal to the average teacher’s salary.15

To remain effective, schools must proactively adapt to evolving challenges and cultivate resilience in an everchanging world. Schools will need to continue to adapt to changing climate conditions (e.g., rising temperatures and extreme weather) and teaching pedagogies. By exploring the interrelationship between pedagogy and school design, it is possible for designers and school decision-makers to create environments that enable occupants to thrive by promoting better learning, health, comfort, and performance.

ABOUT THIS STUDY

This study was conducted to understand how school design can better support today’s learning principles and sustainability objectives by examining past approaches. Specifically, we asked: Is Richard Neutra’s biorealistic approach, which recognizes the intrinsic relationship between people and nature, relevant to today’s changing climate and pedagogical needs? If the answer is yes, what can we learn from the case study of UCLA Lab School, which exemplifies biorealism, to inform school design and educational approaches more broadly?

This study was conducted in a partnership between the global design firm Perkins Eastman, University of California, Los Angeles, and the Neutra Institute for Survival Through Design (NISTD). The study protocol was reviewed and approved by the UCLA Institutional Review Board (IRB#22001505). The multidisciplinary team included researchers, designers, sustainability specialists, and education experts. Using a collaborative process to collect data, we also worked with school administrators, educators, students, and other stakeholders.

We wanted to know:

Is Richard Neutra’s biorealistic approach, which recognizes the intrinsic relationship between people, built environment, and nature, relevant to today’s changing climate and pedagogical needs?

If the answer is yes:

What can we learn from the case study of UCLA Lab School, which exemplifies biorealism, to inform school design and educational approaches more broadly?

RESEARCH QUESTIONS

We examined UCLA Lab School through the dual lenses of architecture and pedagogy to understand how biorealistic design can create comfortable environments that support inquiry-based learning, even as our world’s climate changes.

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Do UCLA Lab School classrooms achieve thermal comfort, and how does thermal comfort differ between naturally ventilated and mechanically ventilated classrooms?

Is the air quality in UCLA Lab School classrooms good, and how does it differ between naturally ventilated and mechanically ventilated classrooms?

How does air quality in UCLA Lab School classrooms compare to that of modern, high-performing schools?

How do inquiry-based learning activities in UCLA Lab School classrooms affect thermal comfort and indoor air quality?

In what ways can lessons from UCLA Lab School’s biorealistic design and inquiry-based pedagogy be applied to other schools to improve indoor environmental quality, well-being, and performance?

DEFINITIONS

MECHANICALLY VENTILATED CLASSROOMS:

Classrooms that provide fresh air circulation and thermal comfort through mechanical systems both ventilating and conditioning the air (heating and cooling)

Note: The mechanically ventilated classroom that we studied was not in the portion of the building co-designed by Richard Neutra. It was added to the campus at a later date.

NATURALLY VENTILATED CLASSROOMS:

Classrooms that rely on operable windows, doors, and/or other passive design features to provide airflow and thermal regulation without mechanical conditioning

METHODOLOGY

Data Collection Strategies

This mixed-method study used four data collection strategies: three-dimensional building modeling and simulation, IEQ on-site measurement using sensors, occupant questionnaires, and observation of classroom activities.

Three-Dimensional Building Modeling and Simulation*

Using Rhino paired with Grasshopper software, plus various analysis plug-ins, we created a digital model of UCLA Lab School buildings to run simulations based on both current and future predictive models of climate change for the local region. This information was used to understand the effectiveness of the passive strategies employed in Neutra’s design, as well as recognize where improvements were needed in light of evolving climate conditions. To identify potential improvements, we tested minor modifications to the building model. This helped us visualize how passive strategies, such as daylight and natural ventilation, could be enhanced by small-scale architectural interventions, with the goal of delivering comfort without the addition of active systems.

IEQ On-Site Measurements

To gauge existing conditions, IEQ sensors were deployed within the building at two points in time: September

2022, when local outdoor temperatures were warm, necessitating air cooling methods, and April 2023, during the heating season, when local outdoor temperatures were cool.

For IEQ data collection, we deployed sensors in both mechanically and naturally ventilated spaces. We selected several classrooms for this study as well as one of the shared spaces located between paired classrooms to be a representative sample of the typical conditions at UCLA Lab School. During the first phase of IEQ data collection, in fall 2022, we deployed sensors in naturally ventilated classrooms; we did not include mechanically ventilated classrooms because the study plan only focused on how the original building had stood up to current climate conditions. After the initial look at the fall 2022 data, we realized that the school had low CO2 levels and a decent temperature, so we decided to identify the IEQ differences between naturally and mechanically ventilated classrooms. Therefore, in the second phase of IEQ data collection, in spring 2023, we added one mechanically ventilated space to the sample. This study was conducted before the installation of HVAC systems in UCLA Lab School classrooms. As of fall 2025, all classrooms at UCLA Lab School are equipped with airconditioning systems.

For thermal comfort, we used HOBO MX1102A data loggers to capture air temperature and humidity. To assess acoustics, sound levels (decibels: dBA) were collected using a Tenma 72-947 data logging sound meter. Based on an occupancy tracking worksheet completed by each classroom’s teacher, we were able to divide sound level measurements into “occupied” and “unoccupied” hours, so average background noise levels could be evaluated separately from occupied noise levels. Daylight was studied by taking measurements that captured its distribution throughout the classrooms. Daylight was the only data collected live, with point-in-time measurements, as opposed to the other IEQ data, which were logged over consecutive days. Daylight measurements were taken using an Extech EA33 illuminance meter on a single day when the classrooms were unoccupied. Measurements were taken on an approximate 5′ 0″ grid throughout the classroom spaces. The air quality data was gathered from two sensors: a HOBO MX1102A to track CO2 levels and a PurpleAir PA-II SD to track particulate matter (PM 10/2.5). Although CO2 levels, when viewed on their own, are not necessarily comprehensive indicators of air quality, they are indicators of ventilation effectiveness and can be used as reflectors of air quality.16 We were not able to study volatile organic compounds (VOCs), either individually or holistically (total volatile organic compounds or TVOCs), because the sensors on the market that capture accurate data were not economically feasible to deploy for this study.

Occupant Questionnaires

To understand perceptions about the school building and campus, including comfort levels, we distributed a questionnaire to occupants in October 2022 and May 2023. We chose this timing to correspond with the IEQ data collection that was based on cooling and heating seasons and local outdoor temperatures. The content of the questionnaire focused on building occupants’ perceived comfort regarding classroom IEQ and the school design’s impact on learning, environmental stewardship, and diverse needs. A question was also included to capture the room in which the respondent primarily learned or worked. This enabled us to compare any differences in the data between the rooms that were naturally ventilated and those that were mechanically ventilated.

Three versions of the questionnaire were crafted such that only relevant questions went to each participant group: an online questionnaire for the school’s faculty, staff, and administrators; a hardcopy questionnaire for the students in third and fourth grades; and a drawingbased hardcopy worksheet for the students in prekindergarten, kindergarten, first grade, and second grade. All questionnaires were anonymous, and the results were sent directly to one of the study’s principal investigators for data entry and analysis.

Questionnaire responses

Example of field notes taken during on-site observations

Classroom Observations

To help with observations, we developed a template for field notes that included several questions and a classroom floor plan. The template was piloted and reformatted several times before its actual use to capture the conditions of the physical environment as well as behaviors during inquirybased learning. The recorded information included the positions of the doors, windows, and curtains (i.e., opened or closed); the number of people in the classroom and where they were located (e.g., seating configurations); people’s movements within the room and their destinations upon exiting (e.g., outdoor patio); and the type of learning activities occurring in the classroom across the day of observation. The researcher who conducted classroom observation used a tablet device to take site photography and to answer the questions and annotate the floor plan in the field notes template (see example on page 20). We performed on-site observations in five UCLA Lab School classrooms (all naturally ventilated) over the course of one school day.

Data Analysis

We divided the data analysis process into two parts: (1) building-performance and future-proofing analysis; and (2) classroom environmental quality and comfort analysis. The first part focused on assessing the building’s ability to withstand the test of time through climate analysis, wind study, ventilation and daylight simulations, and energy-use efficiency analysis, while also identifying strategies to help future-proof the building. The second part of the analysis focused on understanding classroom IEQ and comfort in terms of the relationship between classroom conditions (IEQ, windows and door openings) and occupants’ behaviors stemming from inquiry-based educational practices. Descriptive and inferential statistics were used to analyze the data, and graphs were created to address research questions related to IEQ (i.e., whether UCLA Lab School classrooms achieve thermal comfort and have good indoor air quality); the differences that may exist between natural and mechanically ventilated rooms; and how UCLA Lab School air quality data compares to data from contemporary, high-performing schools. We also compared data from the on-site measurements with questionnaire data to understand the relationship between objective and subjective assessments of the classrooms’ IEQ.

STUDY TIMELINE

Researchers at Perkins Eastman began discussing collaborative opportunities with Neutra Institute for Survival Through Design in summer 2020. The opportunity to commence the study occurred in summer 2022, when Perkins Eastman employed a research fellow, Ruisheng Yang (then a master of architecture candidate at Columbia University’s Graduate School of Architecture, Planning and Preservation), to conduct the 3D modeling and predicted climate change simulations aimed at identifying strategies to future-proof UCLA Lab School. Thereafter, the study expanded to include pedagogical considerations, a comprehensive assessment of indoor-outdoor environmental quality, and the relevance of Neutra’s biorealism to today’s school designers and decision-makers. Overall, the study was conducted from 2022 to 2025, before the installation of mechanical systems in all UCLA Lab School classrooms.

PHASE 1

Study Initiation and Planning

PHASE 2

Methodology Development

PHASE 3

Data Collection

PHASE 4

Data Analysis and Findings

PHASE 5

Reporting

Exploratory and feasibility planning; precedent research and literature review; development of the comprehensive plan (scope, methods, schedule, budget) Mar–Sep 2022

Sample identification; tool procurement/development; data collection prep and site coordination; selection and training of data collectors; obtainment of school clearances for data collectors; Institutional Review Board approval process

Quantitative analyses; qualitative analyses; outcomes review and development of recommendations; data visualization

Report creation and publication design; reviews by UCLA Lab School and NISTD

FINDINGS

In this report, we focus on the results for thermal comfort and air quality, as our research questions centered on these variables. Findings related to daylight and acoustics can be found in Appendices A and B, respectively.

THERMAL COMFORT

A key focus of our analysis was to assess differences in thermal comfort between naturally and mechanically ventilated classrooms based on measured temperatures and occupants’ perceptions. Our analysis of on-site measurement data showed that classroom temperature consistently fell within the ASHRAE thermal comfort range of 68°F to 75°F, both on average and during most periods when the rooms were occupied. We then factored in the questionnaire data regarding occupants’ perceptions of thermal comfort to see whether the difference in ventilation type (mechanical or natural) impacted perceived thermal comfort during two conditions: the cooling season (when the outdoor temperatures are warm) and the heating season (when outdoor temperatures are cool).

UCLA Lab School is located in Los Angeles, CA, which has moderate-to-strong coastal influence with mild winters and warm summers. Given its location, we hypothesized that the naturally ventilated classrooms would be more comfortable in spring (heating season). To test this, we calculated the average temperature for both types of classrooms in the two seasonal conditions.

As seen in the graph on the opposite page, the naturally ventilated classrooms’ average temperature was 75.7°F during the cooling season (slightly above ASHRAE’s recommended comfort range), and 71.8°F during the heating season (falling in the middle of the recommended comfort range).

Because temperatures normally fluctuate throughout the day, we also calculated the percentage of time when temperatures were within ASHRAE’s thermal comfort range during the periods when classrooms were occupied. We found that approximately 53% of occupied time was within the comfort range during the heating season, but the naturally ventilated classrooms were only comfortable 38% of the occupied time during the cooling season. These findings confirmed our assumption that, in Los Angeles climate, the temperature of naturally ventilated classrooms is more likely to be within the comfort range of 68 to 75°F when the outside temperature is cooler.

For the mechanically ventilated classroom in the heating season, we found that the average temperature was 71.5°F, which was nearly the same as the naturally ventilated classrooms, only a 0.3°F difference. However, we did notice a difference between the two types of classrooms in the stability of temperatures over time. The mechanically ventilated classroom we studied had temperatures within the thermal comfort range 97% of occupied times, compared to 38 to 53% (depending on the season) in the naturally ventilated rooms. As seen in the graph to the right, the classroom with mechanical ventilation maintained its temperature within the thermal comfort range for most of the time, whereas the classrooms with natural ventilation had greater fluctuations—sometimes dipping below 68°F and rising above 75°F, often in relation to the current outdoor temperature.

In Los Angeles’ climate, the school’s naturally ventilated classrooms stayed in the comfort range more often during cooler outdoor conditions.

Average indoor and outdoor temperatures across cooling and heating seasons

Temperatures in mechanically and naturally ventilated classrooms

During heating season, the average measured temperatures were nearly the same across the mechanically and naturally ventilated classrooms (71.5°F vs. 71.8°F, respectively).

Mechanical systems provided stable comfort, while natural ventilation had wider temperature swings tied to outdoor conditions.

Perceived thermal comfort in mechanically and naturally ventilated classrooms

To further assess the relationship between ventilation type and occupants’ thermal comfort, we compared the thermal comfort ratings on the questionnaire from respondents in mechanically ventilated classrooms to those in naturally ventilated classrooms. We hypothesized that air-conditioning in a classroom would be associated with greater thermal comfort satisfaction. Indeed, we found that more people in the mechanically ventilated classrooms reported being comfortable compared to those occupying the naturally ventilated classrooms.

To determine whether ventilation type was significantly associated with perceived thermal comfort ratings, we conducted a chi-square test of independence. This test assessed the relationship between two categorical variables: classroom ventilation type (mechanical vs. natural) and occupants’ perceived thermal comfort (comfortable vs. uncomfortable). We found a statistically significant relationship between ventilation type and perceived thermal comfort (χ²(1) = 19.65, p < 0.001), suggesting that occupants in mechanically ventilated classrooms were more likely to report feeling comfortable than those in naturally ventilated ones.

Even though the mechanically ventilated classrooms were rated in the questionnaire as more comfortable than the naturally ventilated classrooms, it is important to note that a majority of occupants in the naturally ventilated rooms also

Perceived comfort was higher in mechanically ventilated classrooms, even though measured temperatures were similar.

reported feeling comfortable during both the heating and cooling seasons. To further explore seasonal differences, we analyzed questionnaire data to assess whether perceived thermal comfort varied between the heating and cooling seasons within each ventilation type. For mechanically ventilated classrooms, the chi-square test revealed a statistically significant difference in perceived comfort between seasons (χ²(1) = 5.92, p = 0.015). A greater proportion of occupants reported feeling comfortable during the spring (88%) compared to the fall (78%). In contrast, for naturally ventilated classrooms, the chi-square test indicated no statistically significant difference (χ²(1) = 0.54, p = 0.461), suggesting that changes in outdoor temperature had little impact on occupants’ perceived thermal comfort in those classrooms. These findings point to an important opportunity for UCLA Lab School and other schools: enhancing passive design strategies and educating occupants about adjustments to behavioral and classroom use can improve perceived thermal comfort without requiring additional mechanical conditioning

Another finding is worth noting: although the mechanically ventilated classrooms had higher thermal comfort ratings on the questionnaire (i.e., occupant perceptions), the actual on-site measurements revealed temperatures were nearly the same across mechanically ventilated and naturally ventilated classrooms. The discrepancy we saw between subjective thermal comfort ratings and actual

temperature data suggests the influence of external factors on people’s perceived thermal comfort. We suspect that a psychological effect may be at play, in which occupants of mechanically ventilated classrooms feel more comfortable simply because of the presence of the mechanical system, regardless of the actual temperature. This is based on two suppositions: (1) it is conceivable that the presence of a mechanical air-conditioning unit gives the room’s occupants a sense of control; and (2) though one’s body temperature can indeed be adjusted via convection or an evaporative cooling process, the noticeable presence of airflow over one’s skin may be associated with thermal comfort.

Our analysis of the air flow measurements in the classrooms supports this hypothesis. Specifically, we identified a lack of air flow in the naturally ventilated classrooms that prevented the cooling of those rooms. Although the average measured temperature was similar in the mechanically and naturally ventilated spaces, the difference in air speed may be what is impacting thermal comfort, contributing to the difference in perceived thermal comfort ratings on the questionnaire between occupants of mechanically and naturally ventilated classrooms.

KEY FINDINGS: THERMAL COMFORT

The average measured temperatures were nearly the same across mechanically and naturally ventilated classrooms.

Although average temperatures were nearly the same, occupants rated mechanically ventilated classrooms as more comfortable, reflecting factors beyond temperature such as airflow and sense of control.

Naturally ventilated classrooms tended to stay within the comfort range during periods of cooler outdoor temperatures.

Temperature fluctuations throughout the day were more variable in naturally ventilated classrooms.

Implementing passive design strategies and adapting occupant behavior can enhance thermal comfort without complete reliance on mechanical systems.

AIR QUALITY

Mechanical ventilation does not only impact a classroom’s thermal comfort; it also affects the classroom’s indoor air quality. To investigate the potential difference in air quality between mechanically ventilated and naturally ventilated classrooms, we evaluated two indoor air quality variables: carbon dioxide (CO2) and particulate matter (PM2.5). As noted in the Methodology section, CO2 levels are often used as an indicator of the effectiveness of ventilation, which is also a reflection of air quality. Therefore, we used CO2 measurements to compare the ventilation performance between mechanically and naturally ventilated classrooms.

In 2023, the global atmospheric CO2 levels were around 420 ppm.17 In UCLA Lab School’s naturally ventilated classrooms, during both heating and cooling seasons, the average CO2 level measurements were only slightly above global levels, indicating that the classrooms have good ventilation rates. However, in the heating season, the mechanically ventilated classroom’s average CO2 level was higher—almost double that of the naturally ventilated classrooms.

When evaluating the maximum measured CO2 levels, we found that the highest reading in a naturally ventilated classroom was 884 ppm in the cooling season, which is below the 970 ppm recommended maximum CO2 level for very young children.18 In the heating season, however, the maximum CO2 level reading was higher, with a naturally ventilated classroom peaking at 1233 ppm. This compares to the mechanically ventilated classroom’s peak CO2 level of 1675 ppm, which is considerably higher still.

Such high CO2 levels in the mechanically ventilated classroom were an indication that this space did not receive as much fresh air. This may be because occupants in mechanically ventilated classrooms are hesitant to open windows and exterior doors to avoid interfering with a building’s air-conditioning system. It may also be due to the mechanical ventilation system itself, which is not providing enough air changes or fresh air to prevent CO2 from accumulating in the space over time. In naturally ventilated classrooms, however, occupants are more likely to open windows or doors, which allows fresh air to flow through these spaces and helps prevent escalating CO2 levels.

Average and maximum CO2 levels across seasons

Naturally ventilated classrooms maintained

CO₂ levels close to outdoor baselines, whereas the mechanically ventilated classroom reached nearly twice that level during heating season.

Comparison of average classroom CO2 levels: UCLA lab school vs contemporary high-performing schools

Of course, what may be considered a high or low CO2 level rating is relative to the bar being set. Though we did find the mechanically ventilated UCLA Lab School classroom had higher average CO2 levels during the heating season than the naturally ventilated rooms we studied, our investigation revealed another interesting finding. To address our research question about how UCLA Lab School classroom air quality stands up against air quality in contemporary highperforming schools, we compared the data we measured in UCLA Lab School to equivalent data we had collected at Benjamin Banneker Academic High School and John Lewis Elementary School in Washington, DC—two new schools designed by Perkins Eastman to the current best practices set out by LEED and WELL standards. We discovered that the 1950s biorealistic classrooms, which embrace design features and occupant-behavioral strategies that promote natural ventilation, considerably out-performed the CO2 levels of both contemporary schools, which are reliant on mechanical ventilation (albeit highly sustainable mechanical systems specifically designed to create healthy indoor environments). This finding underscores the value of what we can learn from Neutra’s design approach.

Next, when looking at the variability of particulate matter for indoor air quality, we saw results that contrasted with our CO2 findings. The PM2.5 levels in the mechanically

UCL A Lab School’s 1950s biorealistic design achieved lower CO₂ levels than contemporary high-performing schools.

ventilated classroom were lower than in the naturally ventilated classrooms. Though Room A, the only mechanically ventilated room in the sample, had the highest measured CO2 level, it also had the lowest PM2.5 level. This is likely a result of this room’s air-conditioning unit, which includes an air filtration system that would help reduce the room’s PM2.5 concentration. As noted earlier, mechanically ventilated classrooms are also more likely to have closed windows and doors, preventing the circulation of outdoor-indoor air throughout the day. Circulation of outdoorindoor air can help lower the amount of CO2 in a room (as evidenced by the naturally ventilated classrooms’ lower CO2 levels). However, outside air may also bring in airborne particulates, like dust and pollen, which typically results in a higher accumulation of particulate matter in naturally ventilated classrooms (rooms B, C, and D).

As captured by the questionnaire, air quality in both mechanically and naturally ventilated classrooms received an overwhelmingly positive rating from both surveyed teachers and students. In mechanically ventilated classrooms, 93% of respondents reported feeling comfortable, noting air that felt “fresh/clean,” compared to 80% of respondents in naturally ventilated classrooms. To explore this further, we conducted a chi-square test of independence to assess whether ventilation type was

Average PM2 5 levels across four days during the heating season

Perceived air freshness in mechanically and naturally ventilated classrooms

associated with perceived air freshness. The analysis revealed a statistically significant association (χ²(1) = 23.77, p < 0.001), suggesting that mechanically ventilated classrooms tend to have a higher proportion of occupants who perceive the air as fresh compared to naturally ventilated classrooms. Again, there may be a psychological effect at play: the perception that an air-conditioning unit provides cool and fresh air could influence an occupant’s rating of the air’s freshness, resulting in a more positive

The mechanically ventilated classroom has lower PM2.5 levels than the naturally ventilated classrooms.

Mechanically ventilated classrooms had a higher proportion of occupants who perceived the air as fresh, compared to those in naturally ventilated classrooms

view of mechanically ventilated classrooms. It could also be that perceived satisfaction is more correlated with PM2.5 than CO2 levels—which matches the findings of our previous study, “Addressing a Multi-Billion Dollar Challenge: Advancing Knowledge of How High-Quality School Environments Can Positively Affect Educational Outcomes,” which explored the impact of IEQ in public school buildings.19

KEY FINDINGS: AIR QUALITY

Naturally ventilated classrooms maintained CO2 levels just above outdoor baselines (~420 ppm20 ), while the mechanically ventilated classroom in heating season reached nearly double that level.

On the contrary, PM2.5 levels were lower in the mechanically ventilated classroom than in naturally ventilated classrooms.

High CO2 levels in the mechanically ventilated classroom indicated limited fresh air supply due to closed windows/doors and insufficient air changes from the system.

The air filtration system integrated into the air-conditioning unit may help reduce PM2.5 levels in mechanically ventilated classrooms.

Opening windows and doors in naturally ventilated classrooms can lower CO2 levels by bringing in fresh air, but may also introduce outdoor contaminants that elevate PM2.5 levels.

Mechanically ventilated classrooms had a higher proportion of occupants who perceived the air as fresh, compared to those in naturally ventilated classrooms.

Occupants rated air quality higher in mechanically ventilated classrooms, likely influenced by the common belief that air-conditioning provides cooler, fresher air.

A CROSS-COMPARISON OF CLASSROOM ACTIVITIES, TEMPERATURE, AND CO 2 LEVELS

We recognize classrooms’ thermal comfort and air quality normally fluctuate, influenced by such factors as the way occupants use a space or the opening and closing of doors and windows throughout the day. Thus, the next stage of our analysis involved a cross-comparison of classroom activities, temperature, and CO2 levels. This allowed us to address our research questions by focusing on how inquiry-based learning activities may affect thermal comfort and/or quality. The cross-comparison also allowed us to further explore the discrepancies we found between objective measurements and subjective ratings described in the previous sections of this report.

The data related to classroom activities were derived from the observations performed in five of the sample’s classrooms (all naturally ventilated), where we had also

collected thermal comfort and air quality data. Recognizing that the inconstant aspects of the physical environment could affect the IEQ, we intentionally tracked such things as occupancy, seating configurations, people’s movement within the space, and window and door conditions (open or closed). Overlapping the observation data with IEQ sensor data furthered our understanding of the dynamics of classroom temperature and CO2 levels throughout the day.

The relationships we found between activity and IEQ were diagrammatically visualized for each room. Each diagram has two y-axes: the left side indicates the temperature; the right side indicates the CO2 levels. Below the x-axis, time of day, we layered on information from the classroom observation data. This was represented using graphic icons.

ROOM B

On this day in Room B, all internal doors and windows were closed the entire day, excluding when people entered or exited the room through the doors. All external windows and doors were fully closed the entire day, except for one external door. The indoor temperature was between 8.6°F and 14.2°F warmer than the outdoor temperature. PM2.5 levels in the classroom mirrored the dynamics of outdoor PM2.5 levels—but the number was higher, reaching unhealthy levels. For the CO2 levels, we found the fluctuation reflected the room’s occupancy, with the highest CO2 levels happening during the longest period of occupancy, which was in the morning. From the start of class at 8:20 a.m., the CO2 levels continued to increase, with a steeper progression when students were especially active in the classroom. During the first scheduled break, starting at 10 a.m., students went outside to eat their snack and play. With the classroom unoccupied, the CO2 levels dropped quickly. As students returned, however, CO2 levels rose again, though not as high as the earlier period. When students left for their lunch break, the CO2 in the room dropped again. When students came back to the classroom, the CO2 levels gradually increased, and they decreased again after students left the classroom for a program held in another part of the school.

Diagram of activity and environmental quality factors in Room B (April 27, 2023)

ROOM C

On this day in Room C, we documented the greatest number of opening and closing of external doors and windows among our observed sample. From the measurements of both activity and IEQ factors in this classroom, we were able to observe the direct impact that outdoor air circulation had on indoor CO2 levels. In the morning, between 8:30 and 9:10 a.m., all internal and external doors and windows were closed, causing the CO2 levels to rise rapidly as students entered and participated in activities within the classroom. Then, at 9:10 a.m., one of the sliding doors was partially opened, resulting in a slow decrease of CO2 levels, followed by a rapid decrease starting at 10:00 a.m., when students went outdoors for their first scheduled break. Between 10:35 and 11:40 a.m., students were back in the classroom and doing movements, from no-movement (sitting in a chair) to high-movement activities (measuring objects around the classroom) sequentially. Corresponding to this, we saw the CO2 levels increasing in direct relation to the amount of movement (i.e., more movement, more CO2), indicating that occupants’ movement directly affected CO2 levels in the classroom. However, more of the classroom windows and doors were opened during this period, so CO2 levels did not rise as high as they did during the morning period. When students were out of the room for lunch, CO2 levels decreased. We did, however, see an unexpected spike in CO2 between 12:30 and 12:40 p.m., despite no activity being recorded in the space. This could have multiple explanations, such as someone briefly entering the room during the lunch break. For the rest of the day, the fluctuation of CO2 levels matched the earlier use pattern. In terms of indoor temperature, this classroom was between 2.8°F and 14.4°F warmer than outdoor temperatures—a smaller differential than seen in Room B, where the exterior doors/windows were mostly closed; the temperature difference between indoors and outdoors is lower when more doors and/or windows are opened.

Diagram of activity and environmental quality factors in Room C (April 19, 2023)

ROOM D

On this day in Room D, the indoor temperature was between 7.5°F and 14.8°F warmer than the outdoor temperature. In fact, this classroom’s temperature was quite warm from the beginning of the day (starting at 73°F). We thought that perhaps the heater in the room had been running overnight or turned on earlier that morning. As in the other classrooms we observed, the CO2 levels in this space reflected classroom occupancy: CO2 levels increased as students entered and were active within the classroom and decreased when they left the classroom during scheduled break times. In general, however, this classroom had lower overall CO2 levels due to doors being opened during occupancy, allowing cross-ventilation to take place.

Diagram of activity and environmental quality factors in Room D (April 20, 2023)

ROOM E

On this day in Room E, the indoor air temperature was between 7.3°F and 12.7°F warmer than the outdoor temperature. The internal doors and windows were closed the entire day, excluding when people entered or exited the room. The external doors were partially open in the morning, closed for a short period of time from 9:30 to 9:35 a.m., but reopened for the rest of the day. Overall, the CO2 levels reflected the classroom occupancy and students’ movements. At 8:20 a.m., when students first entered, the CO2 levels increased, but then quickly decreased when students left to go to the library and had their first scheduled break. Starting at 9:30 a.m., students were back in the classroom, and CO2 levels increased again. After reaching their peak at 10:20 a.m., the CO2 levels gradually decreased as students’ movement also slowed down. CO2 levels decreased more rapidly once students went outside to play between 11:00 and 11:20 a.m. The PM2.5 levels in the classroom were measured high, reaching an unhealthy range—though general fluctuation of indoor PM2.5 levels mirrored the outdoor PM2.5 levels. Since we saw PM2.5 levels lower when students’ movements were reduced, the increased PM2.5 levels were likely caused by students’ movements, which made more particulate matter float in the air.

Diagram of activity and environmental quality factors in Room E (April 27, 2023)

ROOM F

On this day in Room F, all internal doors and windows were closed, excluding when people entered or exited the room. The external doors were open all day and possibly had been left open during the previous night because the indoor air temperature was the same as the outdoor temperature at the beginning of the school day. The classroom’s temperature throughout the day was mostly lower than the outdoor temperature, with the largest gap 5.4°F cooler. Like the other classrooms we’ve discussed herein, the CO2 levels in this space showed a relationship with classroom occupancy: CO2 levels increased when students entered and stayed in the classroom and decreased when students left the classroom during scheduled breaks. Between 9:30 and 11:00 a.m., there was a change in movement levels, but it was not reflected in the CO2 measurements.

Diagram of activity and environmental quality factors in Room F (April 20, 2023)

THE “FRESH-AIR BREAK” EFFECT

Triangulation analysis of air temperature, CO2 levels, and classroom observation data allowed us to understand the relationship between human behavior and IEQ. As expected, CO2 levels rose when the classroom became occupied and when students were active. We also found this increase in CO2 levels to be more rapid when a classroom was sealed off from outdoor air by closed doors and/or windows. In contrast, the circulation of outside air that occurred when doors and windows were opened, helped prevent very high CO2 peaks during the learning period. The most effective way to decrease a classroom’s CO2 levels, however, was for occupants to leave the space. In fact, when the room was not occupied, its CO2 levels quickly lowered, thereby becoming a better environment for occupants upon their return to the classroom. This is

important since research has shown that lower CO2 levels are associated with greater alertness and improved cognitive function.21 22

Thus, we propose that schools can improve learning by using what we are calling a “fresh-air break” to decrease CO2 levels. A fresh-air break, in this case, is for the room, not the people in the room, though they may choose to go to a place with abundant fresh air. A fresh-air break allows the room’s CO2 levels to decrease, preparing the environment for a better learning experience.

FRESH-AIR BREAK

Reset indoor air quality to healthier levels

We propose a “fresh-air break” for classrooms when occupants have been particularly active or the room has been occupied long enough for CO2 levels to rise. This break requires people to leave the room, so CO2 levels can decrease and reset to an optimal condition that supports cognitive function and provides a better learning experience.

KEY FINDINGS: A CROSS-COMPARISON

OF CLASSROOM ACTIVITIES, TEMPERATURE, AND CO 2 LEVELS

CO2 levels were closely tied to occupancy: concentrations increased during classroom use and decreased during scheduled breaks.

CO2 levels were also closely tied to activity levels: as students physical movement within the classroom increased, CO2 levels rose correspondingly.

Opening doors or windows to bring in fresh air lowered CO2 levels in classrooms.

PM2.5 levels increased when students were more active because more particulate matter was stirred up and floating in the air.

Opening doors and windows in naturally ventilated classrooms reduced the temperature gap between indoors and outdoors, resulting in indoor temperatures that mirrored outdoor changes throughout the day.

LESSONS LEARNED AND STRATEGIES FOR TEACHERS,

DESIGNERS, AND BUILDING OPERATORS

The most noticeable biorealistic design element at UCLA Lab School is the seamless integration of the school building with its natural surroundings. Situated within a landscape that includes groves of trees, a creek, and other natural features, the school’s connection to the outdoors is enhanced by large, sliding glass doors that open directly from every classroom to the site’s outdoor work and play areas. This strong indoor-outdoor relationship provides valuable exposure to natural light, fresh air, naturebased sensory experiences, and nontraditional learning settings, which combine to foster a dynamic and engaging educational atmosphere. The site’s surrounding forest plays a crucial role in creating a microclimate that helps regulate classroom temperatures, reduces the need for mechanical heating and cooling, and promotes energy efficiency. Biorealistic school design not only enhances student well-being but also reflects a commitment to sustainable architecture.

UCLA Lab School was initially intended to be naturally ventilated. However, changes in the outdoor environment, such as increasing global temperatures and worsening air quality, have compelled school leadership to amend the design and equip all classrooms with air-conditioning units. These modifications may seem to provide better

thermal comfort, but they could potentially weaken UCLA Lab School’s indoor-outdoor connections, which are an important aspect of its architecture and pedagogical approach. Air-conditioned classrooms typically need to have all their doors and windows closed to stabilize their temperature, which will reduce students’ connections to the natural world (such as exposure to wind, nature sounds, etc.) and their indoor-outdoor learning opportunities.

In our temperature comparisons, there were no substantial differences between mechanically ventilated and naturally ventilated classrooms. In fact, during heating seasons, we found that the average temperature difference in the heating season between the mechanically and naturally ventilated classrooms was less than one degree Fahrenheit. In terms of air quality, the two variables we evaluated (CO2 and PM2.5 levels) exhibited opposite trends in mechanically and naturally ventilated classrooms: CO2 levels were higher in the mechanically ventilated classroom and lower in naturally ventilated ones, whereas PM2.5 levels were lower in mechanically ventilated classrooms (likely due to the system’s air filtration) and higher in naturally ventilated classrooms, where open windows and doors allow fine particulates to infiltrate the air.

Introducing mechanical ventilation may be a simple solution, but there are other options that can be more environmentally sustainable and in alignment with UCLA Lab School’s pedagogical approach

Giving occupants control over their space can be as effective, or even more effective, in achieving comfort than relying solely on mechanical systems.

Why, then, do occupants’ perceptions of thermal comfort and air freshness skew more positively in regard to mechanically ventilated spaces? We theorize that mechanical ventilation systems, such as an air-conditioning unit in a classroom, provide occupants with a perception of control; they can set the system to a desired temperature. The stability of temperature and air flow that airconditioning provides may also influence such preference for mechanically ventilated classrooms, compared to the fluctuations of temperature and air flow throughout the day in naturally ventilated classrooms. However, we argue that a naturally ventilated classroom can offer as much—if not more—control to occupants, particularly in a setting like UCLA Lab School. The key to shifting this perception is

education. When people understand when and how best to use the doors and windows in their space to adjust temperature and air flow, they can exert control and improve their thermal comfort.

The number of doors and windows in each classroom, plus their operability and positioning relative to the outdoor landscape, provide many opportunities for occupants to control a classroom’s IEQ. Through our layered analysis of classroom activities, air quality, and thermal comfort, we found evidence of how behaviors and classroom design can improve or worsen IEQ, and, therefore, the learning experience. For instance, we found that students’ level of activity directly relates to the classroom’s CO2 levels—more movement results in higher CO2 levels. Further, if people

in a space choose to keep doors and/or windows closed, minimizing the amount of fresh air that circulates in the room, CO2 levels will continue to escalate.

Knowing that high CO2 levels negatively impact cognitive performance, it is important to show people how they can take control of their environment, whether mechanically or naturally ventilated, through simple behavioral interventions. Options include: thoughtful timing of certain classroom activities; configuring seating in different ways; providing “fresh-air breaks” throughout the day to bring down CO2 levels (e.g., leaving the classroom to visit the school library, locating recess in the gym or outdoors, etc.); and making the opening and closing of windows and doors a purposeful activity to improve air quality and regulate temperature.

It is also important to consider how mechanically ventilated spaces, which may offer occupants predictable and stable thermal comfort, are typically accompanied by a

disconnection from nature. Occupants in mechanically ventilated rooms are often discouraged from opening doors and windows to the outdoors, as this may interfere with the system’s ability to heat or cool. Such discouragement defeats the purpose of biorealism, which advocates for the seamless integration of indoor and outdoor environments to benefit human health and wellness.

From our study of UCLA Lab School, we learned that the simple act of opening or closing a window, or choosing when and where to become active learners, can have a big impact on the IEQ factors of thermal comfort and indoor air quality. When a classroom feels uncomfortable, the solution is not always architectural or mechanical. IEQ and comfort can also be enhanced by occupants’ behavior. Our findings provide a critical step toward school designers, education experts, and pedagogical practitioners working together to identify challenges and propose solutions— through a combined effort of architectural and behavioral strategies—to facilitate optimum learning experiences.

STRATEGIES FOR TEACHERS: PAIRING

BIOREALISM WITH BEHAVIORAL AND PEDAGOGICAL STRATEGIES

As we think about biorealism and the future of education, we must consider teaching and learning approaches in which educators creatively leverage school spaces to support authentic and collaborative learning. The results of this study highlight the need to integrate a school’s design with pedagogical approaches and people’s behaviors to support occupants’ health, well-being, and educational experience.

One of the most important pedagogical movements in the field of education is embodied, multimodal learning that leverages the cultural practices and forms of participation students bring to school. These perspectives honor a diverse range of communication that centers students’ ability to make sense of the world and find meaning. To support authentic and collaborative learning experiences, educators are seeking to limit the time students spend at desks, sitting in their chairs (or any single spot) for long periods. Instead, they want to leverage movement because learning is a dynamic process and activity. Thus, from a learning perspective, the behavioral strategies to gain the greatest benefit from biorealistic design relate strongly with the pedagogical strategies, as they are founded on the strong relationship between indoor and outdoor spaces.

These behavioral strategies, which can be adapted to both the outdoor environment and the architectural features of schools, align with authentic and collaborative learning pedagogies. For example, project-based work encourages students to coordinate with peers, share information, and meet in small groups; this requires students to move throughout the classroom and interact with one another to exchange ideas and build consensus. Activities like projectbased learning and play are crucial in supporting authentic educational experiences; they are also examples of highmovement learning activities that are best scheduled for first thing in the morning, when CO2 levels are at their lowest, or right after a fresh air break. Thus, the behavioral strategies for adjusting and planning for fluctuating temperatures and CO2 levels fit well with the teaching and learning pedagogies that support dynamic interactions while learning.

What makes a space healthy also makes it good for learning

Behavioral strategies that respond to temperature and CO2 fluctuations also fit well with progressive educational approaches.

Our printable guide for teachers offers simple and sustainable strategies to improve thermal comfort, air quality, and connections to nature in classrooms, regardless of the school’s design or local environmental challenges

Giving teachers the ability to improve the learning environment both indoors and outdoors is crucial, but different schools face different challenges. Teacher’s ability to do something as simple as opening an exterior door or window can be impeded by site-specific conditions: areas exposed to industrial emissions, with smog and excessive particulate matter, airborne chemicals, or other pollutants that make the air unsafe; densely populated urban areas where vehicle emissions elevate local CO2 levels; arid regions where dust storms occur; some agricultural areas, such as those that burn croplands; places that are prone to intense natural events like extreme weather, wildfires,

volcanic activity that releases ash or gases, or even high pollen counts during specific seasons; areas where insectborne disease is prevalent; places that experience high humidity levels; and areas that may seasonally experience increased ozone formations at the ground-level. Some schools may be in unsafe neighborhoods, where crime prohibits school doors and/or windows from being open for extended periods, but they can adopt behaviors that can result in positive changes too. The guide on the following pages outlines simple interventions that can be used in a diversity of classrooms and schools to improve thermal comfort, air quality, and people’s connection to nature.

PEDAGOGICAL STRATEGIES

FOR TEACHERS: PAIRING BIOREALISM WITH BEHAVIORAL AND

Classroom activities that require the most movement (e.g., play) should occur first thing in the morning, when CO2 levels are at their lowest.

Activities designed to use the full classroom space (e.g., students dispersed throughout the room in pairs or small groups) can support better airflow.

Collaborative activities that bring students together on a rug or in a tighter space work best right after a fresh-air break, when the room’s CO2 levels are lower.

Activities designed to make strategic use of the time of day, open and closed windows, and natural light can help balance the temperature, create better airflow, promote exposure to sunlight, and limit CO2 levels.

STRATEGIES FOR DESIGNERS: IMPLEMENTING BIOREALISTIC DESIGN STRATEGIES FOR

CONTEMPORARY SCHOOL DESIGN

Nearly a century has passed since Richard Neutra introduced his philosophy of biorealism. The principles of biorealism, however, remain relevant today. In fact, strengthening humanity’s connection to nature through the built environment grows more and more important as technology, urbanization, building practices, and contemporary behaviors push us further away from the natural world around us. More research underscores the inherent need for humans to connect with nature, as disconnection from it leads to stress, reduced cognitive function, and other negative effects on our well-being.23 Biorealism contributes to the creation of healthier buildings and fosters stewardship of the environment by utilizing the building as a teaching tool to demonstrate natural systems and our interconnectedness with nature.

At UCLA Lab School, we found that biorealistic design provides comfortable learning environments that enhance human health and well-being, thereby supporting inquirybased learning. When Neutra and Robert Alexander incorporated the outdoor environment at UCLA Lab School to be integral to the learning process, their design decisions helped generations of students and educators embrace the school and its campus as the “third teacher.” Through our research, we have identified a number of biorealistic design strategies that can be practiced today, enabling contemporary school design to be deeply integrated with behavioral and pedagogical strategies in support of a strong connection to nature.

Strengthening humanity’s connection to nature through the built environment grows more and more important as technology, urbanization, building practices, and contemporary behaviors push us further away from the natural world around us

APPLYING BIOREALISM TODAY

Biorealism’s goal of maximizing people’s connection to nature can be achieved in many ways. In school environments, connection to nature increases opportunities for students to learn in and about their outdoor settings. This results in advancements in students’ physical, psychological, and social development, not to mention greater engagement in and enjoyment of the learning process.24 The implementation of biorealism in school design improves occupants’ health and well-being, enhances the learning experience, and yields numerous other positive outcomes.

Learning from UCLA Lab School and our study’s findings, we propose design strategies on the following pages to create environments that meet functional demands, improve educational experiences and outcomes, promote sustainability, and bring to life Neutra’s biorealistic vision for healthier, happier people. Before applying these proposed strategies, the school’s context—its location, sociocultural characteristics, and other relevant factors—must be considered, as these conditions should guide the decision to deploy any strategy.

In school environments, connection to nature increases opportunities for students to learn in and about their outdoor settings

FOR DESIGNERS: DESIGNING BIOREALISTIC SITES

INTENTIONAL BUILDING ORIENTATION

Orient the new building to take advantage of the sun and wind patterns.

ACCESS TO NATURAL ELEMENTS

Give children opportunities to have unguided explorations, engage in imaginative play, and even practice safe risk.

LANDSCAPE FOR LEARNING

Cultivate edible gardens to connect children with food, and add green roofs to boost biodiversity and create hands-on learning spaces.

LANDSCAPE FOR COMFORT

Use vegetation buffers to separate classrooms from roads or parking, providing privacy and cleaner air. Plant deciduous trees to allow sunlight in winter and offer cooling shade in summer.

SHADE STRUCTURES FOR IMPROVED COMFORT

Add pergolas, canopies, or sails to minimize solar heat and manage glare from seasonal sun angles.

DIVERSIFY SITE VEGETATION

Provide interactive learning opportunities that allow students to explore the life cycle of plants throughout the year.

FOR DESIGNERS: DESIGNING BIOREALISTIC BUILDINGS

YEAR-ROUND, INDOOR-OUTDOOR LEARNING CONNECTIONS

Create direct connection between indoor and outdoor spaces for learning using exterior door to patio, courtyard, or outdoor amphitheater.

BIOPHILIC DESIGN ELEMENTS

Use natural building materials, finishes, patterns, and textures to bring the outside indoors.

ADAPTABLE LEARNING SPACES

Provide adaptable spaces and flexible furniture to accommodate changing pedagogies and supporting educational engagement.

OPTIMAL DAYLIGHT EXPOSURE

Strategically place windows, skylights, or light wells to bring in daylight, which helps regulate circadian rhythms, reduce stress, and improve learning.25

VISUAL CONNECTION TO NATURE

Windows help occupants remain connected to nature while inside, providing opportunities to observe natural dynamics (e.g., waving trees, weather changes, sun movement).

OPERABLE WINDOWS

Operable windows give occupants opportunity to connect with nature’s climate patterns, smells, and sounds, and they allow passive regulation of indoor temperature and air quality.

SENSORY WELL-BEING

Promote sensory well-being with thoughtful acoustic design, tactile experiences, olfactory conditions, and thermal comfort.

PASSIVE HEATING AND COOLING

Use strategies like wide roof overhangs for shading and reducing heat and glare or stone massing to store and release heat. Vernacular design can also inspire sustainable passive solutions.

FUTURE-PROOFING BIOREALISM

As the climate changes and teaching practices evolve, school buildings must be designed with future-proofing strategies in place. In addition to applying biorealistic features, as outlined in the previous section, it is important for designers and decision-makers to implement strategies that increase a school’s adaptability and resilience in a constantly changing world.

When considering how to adapt Neutra’s philosophy to current projects and conditions, it is important to address four IEQ-based strategies to future-proof biorealism.

Future-Proofing Air Quality

Starting early in the design process, we recommend examining the relationship between the school’s site and its surroundings. Early identification of areas that can become the source of pollutants, such as busy streets and gas stations, should inform the placement of building openings, including doors, windows, and vents. Additionally, consider planting trees and vegetation as a natural filter to pollution, thereby improving local air quality. In terms of building systems, we recommend mixed-mode ventilation (also known as hybrid ventilation) in applicable climates.

Mixed-mode ventilation is a space conditioning method that alternates between natural and mechanical ventilation and cooling.26 The mixed-mode ventilation should be paired with operable windows that can be opened or closed depending on the active ventilation system.

To regulate temperatures and achieve good indoor air quality, while also reducing energy consumption, we recommend using passive strategies (like natural ventilation) as much as possible and in accordance with local climate and weather conditions. However, during extraordinary times, such as wildfire season, the building should be sealed from outside air by closing the windows and activating mechanical ventilation systems to filter and purify the air. In this way, a mixed-mode ventilation system supports a building’s versatility, providing air filtration when needed and natural ventilation when preferred. For ventilation systems (and other mechanical and electrical systems), we recommend using all-electric and/or renewable energy that does not emit on-site combustion, which can contribute to poor local air quality.

Future-Proofing Thermal Comfort

Whenever possible, buildings should incorporate passive design, so occupants can remain connected to the natural environment. Passive cooling strategies should be built on an understanding of the local context, both macroclimate and microclimate. Climate analysis should be done to examine exterior environmental conditions such as temperature, humidity, rainfall, wind, and solar radiation. These factors will impact the performance of the building envelope and influence occupants’ thermal comfort. The results of the climate analysis will inform the degree of passive cooling and heating strategies appropriate for the building.

In general, passive cooling strategies can be achieved by improving air flow using natural ventilation in indoor spaces and providing shading systems for outdoor spaces (e.g., trees, shade structures). For passive heating, we recommend improvements in insulation and airtightness

of the building envelope to retain heat and prevent air leakage. Additionally, some locations can benefit from the use of passive solar design—using south-facing windows to collect heat from the sun and store the heat in the building materials.27

As global temperatures rise and the frequency of heat waves increases, ensuring buildings can provide thermal comfort during these events is essential. We advocate for mixed-mode ventilation and conditioning systems that can be turned on when it is no longer safe or comfortable to rely on naturally ventilating the indoor spaces. If air-conditioning is used to cool a space, tightening up the building envelope by keeping the windows and doors closed while the unit is running will help to optimize comfort, minimize air leakage, and reduce energy consumption.

Future-Proofing Acoustics

Building acoustics are affected differently depending on which ventilation system is chosen. For instance, when using natural ventilation for a school located in a busy area, outdoor noise levels can be an issue when doors or windows are open. Trees and vegetation can be used as a buffer when ambient noise needs to be mitigated. When it comes to mechanical ventilation, the presence of a noisy air-conditioning unit in a classroom makes learning difficult for students and fatigues educators who must raise their voices to be heard. To prevent high background noise levels that can distract teaching and learning, noisy HVAC system components should not be placed in or near classroom environments. Sound barriers and sound-absorbing materials added to ceilings and walls can further reduce unwanted background noise in classrooms.

Future-Proofing Daylight

Bringing natural light inside requires strategic consideration of the building’s site orientation, arrangement of classrooms within the overall school building, and location of windows in relation to sun angles. We recommend introducing light high into the space through clerestory windows and pairing them with lower view windows and shading devices oriented to the south, east, and west. In this way, classrooms receive plenty of light without increased glare. Additionally, internal light shelves can be used to divert natural light deeper into the building’s interior. Whenever possible, daylight should enter from two sides of the classroom. It is important to note that daylight strategies are dependent on building orientation. Classrooms may have different orientations and require different daylighting strategies. Teaching surfaces such as screens and whiteboards should be positioned to avoid excessive glare from natural and artificial lighting.

FOR DESIGNERS: FUTURE-PROOFING BIOREALISTIC DESIGN

FUTURE-PROOFING AIR QUALITY

• Examine the source of pollutants (e.g., busy streets, gas stations) to inform the location of building openings (i.e., doors, windows, vents).

• Plant trees and vegetation to naturally filter pollution.

• Use mixed-mode ventilation paired with operable windows (in applicable climates).

• Prioritize natural ventilation as much as possible in accordance with local climate and weather conditions.

• During extraordinary times like wildfire season, ensure buildings are sealable from outside air by closing the windows and activating mechanical ventilation to filter and purify indoor air.

• Use all-electric/renewable energy that does not emit on-site combustion.

FUTURE-PROOFING THERMAL COMFORT

• Conduct climate analysis of the site to inform passive heating and cooling strategies.

• Provide shading systems for outdoor spaces (e.g., trees, shade structures).

• Apply passive solar design (such as south-facing windows for projects in the Northern Hemisphere) that collect and store heat in building materials.

• Use mixed-mode ventilation paired with operable windows (in applicable climates).

• Enhance air flow indoors through natural ventilation.

• Improve insulation and airtightness of the building envelope.

FUTURE-PROOFING ACOUSTICS

• Plant trees and vegetation as natural barriers against outdoor noise.

• Avoid placing HVAC system components near or inside classrooms.

• Incorporate sound barriers and sound-absorbing materials in classroom ceilings and walls.

FUTURE-PROOFING DAYLIGHTING

• Use clerestory windows to bring daylight high into the space.

• Provide lower view windows with shading devices (oriented to the south, east, and west for buildings in the Northern Hemisphere).

• Incorporate internal light shelves to reflect natural light deeper into the building interior.

• Allow daylight to enter from two sides of the classroom.

• Position teaching surfaces (e.g., screens, whiteboards) to avoid glare from daylight or electric light.

STRATEGIES FOR BUILDING OPERATORS: MANAGING BIOREALISTIC BUILDINGS

Biorealism is relevant to designers and building operators alike. Operating under a biorealistic philosophy requires a commitment to nurturing the harmony between architecture and nature to enhance occupants’ health and well-being. To help building operators make this commitment, we offer the following IEQ strategies for biorealistic operations.

Air Quality and Thermal Comfort

Air quality and thermal comfort go hand in hand when operating a biorealistic building. When mechanical systems are turned on, set points should be programmed to seasonal settings, so that heating and cooling systems operate efficiently and maintain comfort throughout the day. When providing mixed-ventilation, cooling, and heating systems, the building operator should establish a process to minimize the concurrent use of natural and mechanical ventilation. One strategy is to alert teachers when the outside conditions are appropriate to open or close the windows in their classrooms, such as using a signal connected to a weather station (e.g., a red-colored light indicating windows should be closed and a green-colored light indicating windows may be opened). Another strategy is to use systems that automatically shut off when the windows are opened and vice versa. A simple yet surprisingly useful strategy is to educate building users as to when and why they should use natural ventilation rather than mechanical ventilation. Given that many people, especially younger generations, are accustomed to mechanical ventilation, it is possible that people need to learn or relearn these time-honored practices.

Regarding air quality, it is important to replace filters on a regular basis to prevent the buildup of pollutants that can deteriorate indoor air quality and a system’s efficiency. Building operators should also prioritize green cleaning products and rigorous daily cleaning practices; naturally ventilated classrooms need to be cleaned more frequently due to the higher likelihood of particulate matter (brought in by outside air) accumulating on horizontal surfaces.

Daylight

At certain times of the day, some classrooms may receive more sun exposure than others. To prevent glare, install internal blinds that can be controlled by the occupants. Window coverings should be semitransparent to allow a view through the material (avoid blackout shades). It is important, however, to ensure that blinds are pulled up whenever teaching and learning will not be disrupted by sun exposure. Encouraging teachers to open and close blinds according to season, weather, and time of day, or use an automatic blind system based on sun exposure, ensures the classrooms’ connection to outdoor spaces remains strong and consistent.

BUILDING OPERATORS

FOR BUILDING OPERATORS: MANAGING BIOREALISTIC BUILDINGS

ENHANCE THERMAL COMFORT

• For fully mechanical systems, program temperature setpoints according to seasonal conditions.

• For mixed-mode systems, reduce overlap between natural and mechanical ventilation:

◦ Notify teachers when outdoor conditions are suitable to open or close windows.

◦ Use visual signals (e.g., red and green lights) connected to a weather station to indicate appropriate times to open or close windows.

◦ Use automated control to open or close windows based on temperature and air quality thresholds.

◦ Educate building users on when and why natural ventilation should be prioritized over mechanical ventilation.

MAINTAIN HEALTHY AIR QUALITY

• Replace filters on a regular basis.

• Use green, nontoxic cleaning products.

• Conduct regular and rigorous daily cleaning practices, especially in naturally ventilated spaces.

ACHIEVE OPTIMAL DAYLIGHTING

• Install semitransparent internal blinds to reduce glare while preserving views.

• Provide occupants with control over the blinds.

• Keep blinds open whenever sunlight does not disrupt teaching and learning.

FINAL THOUGHTS

The central philosophy of biorealism—harmony between architecture and nature to enhance human well-being— remains relevant today. Through our case study evaluation of UCLA Lab School, we pinpointed ways in which Neutra’s biorealistic design principles are contributing to occupants’ well-being and creating learning opportunities as students engage with the natural environment. In the face of challenges like climate change and the continued evolution of educational pedagogy, UCLA Lab School remains agile. Helping with this agility is the school’s adoption of the recommendations outlined in this report to make the most of the building’s windows and doors for natural ventilation. Our recommendations use the classroom as a tool to enhance both the educational process and the IEQ quality of the space.

The lessons learned from this study position UCLA Lab School for future success, and they are also applicable to other schools. The printable guide for teachers (page 55) and the design guidelines (pages 60–63, 68–69) provided in this report are aimed at helping others learn from and adopt Neutra’s philosophy of biorealism. From a combined behavioral, pedagogical, and architectural standpoint, biorealism is a valid and useful approach to creating optimal environmental conditions and learning experiences. Our recommendations regarding biorealistic building operations and behavioral strategies to elevate IEQ are also transferable to other types of buildings, such as workplaces and housing.

This study has several limitations that should be acknowledged when interpreting the findings. First, the response rate to the teacher questionnaire was relatively low, which may limit the representativeness of the perspectives captured. Second, no mechanically ventilated classroom data was collected during the fall 2022 data collection period, restricting the study’s ability to assess the IEQ of mechanically ventilated classrooms during cooling season. Third, the number of sample classrooms was not evenly distributed between the two types of ventilation systems, which may have influenced comparative analyses. Fourth, classroom observations and corresponding outdoor environmental data were limited to a single day, which may not fully reflect the variability of typical weekly activities, temperature fluctuations, and air quality conditions. Future research should consider a larger and more balanced sample, longitudinal data collection across multiple seasons, and repeated observations to better capture day-to-day and seasonal variations.

Nonetheless, this study’s findings challenge overreliance on mechanical solutions to achieve environmental comfort and promote alternative approaches that move school design toward long-term adaptability. By exploring the past through Neutra’s lens of biorealism, assessing current conditions at UCLA Lab School, and addressing future challenges, this study offers strategies for designing sustainable schools that can adapt and thrive amid climate change and evolving teaching practices.

APPENDIX A: DAYLIGHT FINDINGS

Despite the large number of windows and glass sliding doors at UCLA Lab School, our study found that the classrooms do not receive a significant amount of daylight. When we measured daylight during the cooling season (September 2022), we found that more than 99% of the evaluated classroom floor area was underlit—receiving less than 27.9 fc illuminance levels. When we measured again during the heating season (April 2023), the amount of daylight within the classrooms did not change much, with 96% of the area underlit in the morning and 86% underlit in the afternoon. We hypothesize that the building’s wide roof

overhangs combined with the dense tree canopy shading the site (which has grown considerably since Neutra designed the building for the site’s landscaping 70 years ago) likely contribute to the limited daylight penetration in the classrooms. Our hyphothesis was also reflected in the predictive analysis we performed. Further, despite Neutra’s priority around daylight, his designs came before the advent of today’s technology and analytical tools, which allow us to use data to inform better daylight design.

Daylight visualization of sample classrooms measured in fall 2022

SEPTEMBER 2022

% of underlit area: 100% (morning); 99% (afternoon)

% of overlit area: 0% (morning); 1% (afternoon)

Daylight visualization of sample classrooms measured in spring 2023

APRIL 2023

% of underlit area: 96% (morning); 86% (afternoon)

% of overlit area: 0% (morning); 2% (afternoon)

APPENDIX B: ACOUSTIC FINDINGS

Our study’s measurements of acoustic conditions in the evaluated UCLA Lab School classrooms found that, during the cooling season, the average background noise (i.e., noise that comes from within the building or its surroundings, such as the street) registered at 44.2 decibels (dBA). In the heating season, the average background noise decreased to 41.2 dBA, likely due to the closing of windows and/or doors to achieve thermal comfort, which reduced the outdoor noise levels within the classrooms. However, both of these values are slightly higher than 40 dBA, a threshold commonly applied to background noise from mechanical equipment, which we use as a reference in the

absence of outdoor noise standards. In regard to occupied noise levels (i.e., the noise that comes from people inside the classroom), the average occupied noise level was 55.6 dBA in the cooling season and 55.7 dBA in the heating season—both measurements fell within the recommended range. When we evaluated the acoustic data in individual classrooms, however, we identified some spikes in noise, which we were able to link to the types of activity occurring in the classroom based on our field observation data. The highest recorded noise peaked at 90.9 dBA in the cooling season and 91.3 dBA in the heating season.

Sound levels of sample classrooms measured in fall 2022

Sound levels of sample classrooms measured in spring 2023

NOTES

1 Richard Joseph Neutra, Survival Through Design (New York: Oxford University Press, Inc., 1954), https://archive.org/details/survivalthroughd00neut/ mode/2up.

2 Nick Bartzokas et al., “Why Opening Windows Is a Key to Reopening Schools,” The New York Times, February 26, 2021, https://www.nytimes.com/ interactive/2021/02/26/science/reopen-schoolssafety-ventilation.html

3 Bethany Christian Morse, “Richard Neutra, Biorealist” (Thesis, The University of Texas at Austin, 2013), https://repositories.lib.utexas.edu/server/api/ core/bitstreams/5f48de92-e34c-4b25-8e988e4e273e2eaa/content

4 John Elkington, Cannibals with Forks: The Triple Bottom Line of 21st Century Business (Oxford, United Kingdom: Capstone Publishing Limited, 1997).

5 The Neutra Institute for Survival Through Design, “Biorealism Then and Now,” Neutra, accessed March 3, 2025, https://neutra.org/the-institute/what-weredoing/biorealism-then-and-now/.

6 William Browning, Catherine Ryan, and Joseph Clancy, “14 Patterns of Biophilic Design: Improving Health & Well-Being in the Built Environment” (Terrapin Bright Green, LLC, 2014), https://www.terrapinbrightgreen. com/wp-content/uploads/2020/05/14-Patterns-ofBiophilic-Design-Terrapin-2014e.pdf

7 “History UCLA Lab School,” UCLA Lab School, accessed July 1, 2025, https://www.labschool.ucla. edu/about/history

8 Architecture 2030, “Why the Built Environment,” Architecture 2030, 2023, https://www. architecture2030.org/why-the-built-environment/.

9 Erika Eitland et al., “Schools for Health: Foundations for Student Success” (Harvard T.H. Chan School of Public Health, 2017), https://forhealth.org/Harvard. Schools_For_Health.Foundations_for_Student_ Success.pdf; Hanover Research, “School Structures That Support 21st Century Learning” (Hanover Research, March 2011), https://www.sas.edu.sg/

uploaded/Perspectives_Blog_Categories/Hanover_ Research_(1).pdf

10 Anna Phillips and Veronica Penney, “Schools That Never Needed AC Are Now Overheating. Fixes Will Cost Billions.,” Washington Post, May 24, 2024, https:// www.washingtonpost.com/climate-environment/ interactive/2024/school-temperatures-heat-climatechange/.

11 The Children’s Health Protection Advisory Committee, “Report of the Indoor Environment Workgroup on Indoor Environment” (United States Environmental Protection Agency, 2011), https://www.epa.gov/sites/ default/files/2014-05/documents/chpac_indoor_air_ report.pdf

12 Pawel Wargocki, “Ventilation, Indoor Air Quality and Learning in Schools,” September 30, 2015, https:// www.aivc.org/resource/ventilation-indoor-air-qualityand-learning-schools

13 Jisung Park, “Temperature, Test Scores, and Human Capital Production” (Harvard University, 2017), https://scholar.harvard.edu/files/jisungpark/files/ temperature_test_scores_and_human_capital_ production_-_j_park_-_2-26-17.pdf

14 Homa Shalchi, “Excessive Heat and Its Impact on Mental Health,” Baylor College of Medicine, July 24, 2023, https://www.bcm.edu/news/excessive-heatand-its-impact-on-mental-health

15 Marcel Harmon, “Creating Environments That Promote Efficiency and Sustainability: Anthropological Applications in the Building/Construction Industry,” in Proceedings from the 2012 ACEEE Summer Study on Energy Efficiency in Buildings, 2012, 7-75-7–87, https://www.aceee.org/files/proceedings/2012/ data/papers/0193-000228.pdf

16 National Education Association, “How to Evaluate Building Ventilation Using Carbon Dioxide Monitors,” May 2022, https://www.nea.org/sites/default/ files/2022-05/How%20to%20Evaluate%20 Building%20Ventilation_0.pdf.

17 World Meteorological Organization, “WMO Greenhouse Gas Bulletin: The State of Greenhouse Gas in the Atmosphere Based on Global Observations through 2023” (World Meteorological Organization, October 28, 2024), https://library. wmo.int/viewer/69057/download?file=GHG-20_ en.pdf&type=pdf&navigator=1

18 Office of Air Quality Planning and Standards, “Technical Assistant Document for the Reporting of Daily Air Quality” (United States Environmental Protection Agency, September 2018), https://www. airnow.gov/sites/default/files/2020-05/aqi-technicalassistance-document-sept2018.pdf

19 Emily Chmielewski et al., “Addressing a Multi-Billion Dollar Challenge: Advancing Knowledge of How HighQuality School Environments Can Positively Affect Educational Outcomes” (Perkins Eastman, December 2023), https://perkinseastman.com/wp-content/ uploads/2023/12/Latrobe_BillionDollarChallenge_ FullReport.pd

20 World Meteorological Organization, “WMO Greenhouse Gas Bulletin: The State of Greenhouse Gas in the Atmosphere Based on Global Observations through 2023,” https://library. wmo.int/viewer/69057/download?file=GHG-20_ en.pdf&type=pdf&navigator=1

21 Sandra Dedesko et al., “Associations between Indoor Air Exposures and Cognitive Test Scores among University Students in Classrooms with Increased Ventilation Rates for COVID-19 Risk Management,” Journal of Exposure Science & Environmental Epidemiology, April 9, 2025, 1–11, https://doi. org/10.1038/s41370-025-00770-6.

22 Joseph G. Allen et al., “Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments,” Environmental Health Perspectives 124, no. 6 (June 2016): 805–12, https://doi.org/10.1289/ehp.1510037

23 Colin A. Capaldi, Raelyne L. Dopko, and John M. Zelenski, “The Relationship between Nature Connectedness and Happiness: A Meta-Analysis,” Frontiers in Psychology 5 (September 8, 2014), https://doi.org/10.3389/fpsyg.2014.00976 ; Lucy Keniger et al., “What Are the Benefits of Interacting with Nature?,” International Journal of Environmental Research and Public Health 10, no. 3 (March 6, 2013): 913–35, https://doi.org/10.3390/ ijerph10030913 ; Stacy T. Taniguchi, Patti A. Freeman, and A. LeGrand Richards, “Attributes of Meaningful Learning Experiences in an Outdoor Education Program,” Journal of Adventure Education & Outdoor Learning 5, no. 2 (January 2005): 131–44, https:// doi.org/10.1080/14729670585200661

24 Christoph Becker et al., “Effects of Regular Classes in Outdoor Education Settings: A Systematic Review on Students’ Learning, Social and Health Dimensions,” International Journal of Environmental Research and Public Health 14, no. 5 (May 2017): 485, https:// doi.org/10.3390/ijerph14050485 ; Karen Wistoft, “The Desire to Learn as a Kind of Love: Gardening, Cooking, and Passion in Outdoor Education,” Journal of Adventure Education and Outdoor Learning 13, no. 2 (June 1, 2013): 125–41, https://doi.org/10.1080/ 14729679.2012.738011

25 Diego Carlos Fernandez et al., “Light Affects Mood and Learning through Distinct Retina-Brain Pathways,” Cell 175, no. 1 (September 20, 2018): 71-84. e18, https://doi.org/10.1016/j.cell.2018.08.004 ; Anna Wirz-Justice, Debra J. Skene, and Mirjam Münch, “The Relevance of Daylight for Humans,” Biochemical Pharmacology, Circadian Rhythm and Sleep-wake Dependent Regulation of Behavior and Brain Function, 191 (September 1, 2021): 114304, https://doi.org/10.1016/j.bcp.2020.114304

26 Gail S. Brager, Erik Ring, and Kevin Powell, “MixedMode Ventilation: HVAC Meets Mother Nature.,” May 1, 2000, https://escholarship.org/uc/ item/0285m0h1

27 National Renewable Energy Laboratory, “Passive Solar Technology Basics,” accessed October 30, 2024, https://www.nrel.gov/research/re-passive-solar.html

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IMAGE CREDITS

© Julius Shulman photography archive, 1935–2009, Research Library, Getty Research Institute, Accession no. 2004.R.10: cover, ii–iii, iv–v, vii, viii, 4–5, 7, 9, 10–11 (background photo), 13, 14, 16, 28, 32, 45, 46, 48, 56, 72–73, 74, 76

The Noun Project icons: 3, 8, 12, 49–53, 57, 59

Adobe Stock: 4–5, 17 (sketches), 21 (sketches), 66 (sketches)

© Sandra Smith: 10 (bottom right)

© Christine Lee: 10 (top right, bottom left), 11 (top left, top right, bottom left, bottom right), 15, 17, 21, 27, 45 (bottom left), 47, 50, 51, 58, 65, 66

Photographs by Andrew Rugge © Perkins Eastman: 54

© Aisha Villabona from sketchify via Canva.com: 55

© Joseph Romeo: 64, 67, 71