4.12 Power and Lighting
Related SPD sections
• 4.3 Green Infrastructure (re: lighting of and near trees)
• 4.5 Street Furniture (re: lamp columns – location and design and re: Placement of Wi-Fi and Smart technology)
• 4.13 Signs and Adverts
• 4.11 Services and utilities
• 4.7 Street Trading / Commercial Activity (including Tables and Chairs)
Key City Plan policies 43. Public Realm
The City Plan specifies that development should contribute to improving connectivity, legibility and permeability of the public realm and the network of public spaces in the city through: creating clear sight lines, improve lighting and following the principles of designing out crime.
This section focuses on required light levels and the function of lighting in the public realm. Guidance on the placement of lamp columns, and on lamp column and lantern types, is provided in the Street Furniture section above.
Westminster’s Westminster's Master Lighting Plan 2020-2040 and Lighting Design Guide defines a standard of lighting “The Westminster Standard” appropriate to the needs of the council and its highway and public realm users, whilst the Third Party Attachments/Smart Lighting Column Guide requires the light column structure to be assessed to what it can safely support: https://www.westminster.gov.uk/roads-and-travel/street-lighting
These documents lay down a strategic approach to managing the use of artificial light across the city. TfL are responsible for street lighting on the Transport for London Road Network (TLRN 78). Westminster City Council has responsibility for street lighting on Westminster’s remaining streets.
When considering lighting levels, the scale of the space and its component factors must be taken into consideration. Different spaces require different lighting illumination, for instance conservation areas, high security areas, and residential areas.
Context
Street lighting plays an important function enhancing safety and legibility in the public realm and shaping the city’s streetscape after dusk.
Light has the power to reveal or conceal buildings, landscape, and topographical features, highlight and define routes and boundaries, and emphasise views.
It can:
• Aid wayfinding, security, and help create a sense of place.
• Keep our public realm accessible, legible, and safer after dark.
• Reduce the risk of accidents, and increase visibility for emergency services.
• Protect assets, discouraging crime and vandalism.
78 See TLRN Network diagram in Highways Guidance in this SPD.
• Serve as its own form of public art
However, excessive or poor lighting can:
• Create visual overload.
• Detrimentally impact road users, pedestrians, residents, and biodiversity.
Getting the approach to lighting of the public realm right through a coordinated use of artificial lighting supports our nighttime economy and enables the safe movement of people through the city, encouraging dwell time in appropriate locations, and deterring anti-social behaviour.
Where they arise, opportunities to improve the energy efficiency of street lighting and centrally manage lighting levels in response to user needs must be taken.
Additional incidental lighting comes from shop windows, offices, homes, and vehicles. The orientation of entrances and windows to buildings can encourage surveillance and self-policing of public spaces. Good lighting is an important tool in this respect and schemes should consider all artificial light sources both public and private, that may contribute to the highway environment
Third party lighting interventions usually require planning permission Westminster’s Lighting Design guide advises on the required standards to meet.
Pedestrian routes through open spaces should be carefully designed to ensure safety and convenience and have appropriate levels of lighting as well as clear sign-posting and additional safety measures such as camera enforcement and barriers where there is an agreed evidenced need.
Whilst there is no statutory requirement for the City Council to provide street lighting, if a system of street lighting exists it should be lit to required British lighting Standards. We are responsible for the safety of our highway/public realm users and require anyone developing schemes on the public realm to abide by the below Strategic Principles.
Public lighting cannot be viewed in isolation and should never be seen simply as providing a certain fitting with a certain type of lamp.
Lighting proposals must be examined holistically, and provide a balance between safety and security, and sustainability / energy efficiency.
We need to create a coherently lit nightscape, using the latest technology to manage and reduce energy consumption and light pollution, and to increase a sense of safety and security on the streets. Use of light emitting diodes (LEDs) offer opportunities to enliven the city at night with a lower environmental footprint and at reduced cost.
Key Lighting Objectives
• Wayfinding — Through lighting equipment style and application, enable all users to locate themselves and navigate through the city by providing local identities by day and night and the appropriate lighting of key wayfinding landmarks, nodes and routes at both a citywide and local area level.
• Sustainable — Taking a European Commission Green Public Procurement 79 approach to the consideration, planning, design, and operation as well as the application of the right technologies, standards and guidance through a whole life costing approach reduces the energy and carbon footprint and provides a reliable sustainable and maintainable
79 Green Public Procurement (GPP) means that public authorities seek to purchase goods, services and works with a reduced environmental impact throughout their life-cycle compared to goods, services and works with the same primary function which would otherwise be procured. Green Public Procurement is a voluntary tool for Europe's public authorities that favours products, services and works that respect the environment." https://ec.europa.eu/environment/gpp/index_en.htm
lighting installation. This includes working towards a Circular Economy for any component to reduce carbon and prolong a component's life by re-use, recycling etc.
• Environment — Manage the environmental consequences that arise from using artificial light at night with respect to humans as well as our treasured flora and fauna. These objectives are not mutually exclusive but have large overlaps; improving lighting in an area demonstrates investment with that area, promotes safety but also links to developing the local economy and celebrating local distinctiveness, perhaps changing a perception of an area The Council’s Artificial Lighting Environmental and Ecological Impact Strategy details relevant legislations and areas requiring specific attention within the City.
• The City Council will maintain modern street lighting columns and lanterns to a high standard in terms of its physical condition/state of repair as well as in terms of its lighting level and efficiency, with a target of 50 year column life and 20 year equipment life
• It is also important to maintain our historic and cherished lighting assets, maintaining their appearance and fit within the built environment but using modern innovations to light the highway and minimising impact on their aesthetic quality.
• Future Ready — Develop an approach by which the lighting infrastructure is considered to support future technologies associated with good light & lighting practice and Smart City applications. Advising on how these can be assessed, trialled and if suitable brought into standard application.
• Quality in design — Promote quality in the design and application of lighting, undertaken by competent lightings designers, ensuring that Westminster is attractive, welcoming and neighbourhoods continue to thrive.
• Support the night-time economy — good light and lighting practices can significantly enhance the city for residents, tourists, workers, and businesses, drawing people into areas at night.
Sustainability
Energy reduction is an important objective and remote central monitoring systems and new technologies using light emitting diodes (LEDs) have offered new opportunities to enliven the city at night with a lower environmental footprint and at reduced consumption
Technological advancements may provide future opportunities for use of renewable energy, however this would require battery storage issues to be resolved, as the power would be generated mostly in the daytime when it would be needed to power lighting at night. Aesthetic considerations must also be considered with respect to the built environment they are placed in and the council historic column assets.
• Every lighting scheme will consume energy, emit light and require maintenance. The following actions may be taken to control and reduce energy waste and light pollution:
o the use of lower energy light sources
o use of improved optics and lighting design by competent lighting professionals
o the change to the most energy efficient control gear
o the use of remote control and central monitoring systems
o eradication of shabby, non-standard units and damaged equipment.
• The Council is open to testing more sustainable energy sources including solar, wind and kinetic where a positive business case and whole life carbon emissions is proven.
• Materials and equipment, including their delivery and installation, should be procured in a carbon neutral way. See materials guidance in this SPD.
Lighting Guidance
A. Lighting in the public realm must be designed and located to maximise energy and lighting level efficiency, and not detrimentally impact on public realm or highways users, or local residential amenity or biodiversity.
B. They must be of appropriate size and provide sufficient lighting for their setting.
C. Designers are responsible for considering the location, maintenance, repair, clean and eventually demolition and recycling and/or reusability of the structures.
D. Columns should not be placed in front of windows and doors.
E. Lighting can be applied staggered, or one-sided, double-sided, or a mixture depending on the underground conditions and other issues such as windows and trees. Trial holes will need to be dug prior to construction beginning, to ensure no obstructions are in the ground. These may include, but are not limited to, basements and utilities.
F. The use of in-ground uplighters in the public realm will generally not be supported. These are difficult to maintain and their use will be resisted. There are more preferred methods to provide feature lighting above ground that the Council can advise on that will also reduce obtrusive light.
G. Street lamps that are not historic will still have characteristic Westminster bases if in prominent locations, but there will be places calling for a simpler approach with undecorated stepped tubular columns with standard functional lanterns.
H. All street lamps will use the council’s current central monitoring system (CMS)
I. Safely lighting streets is the priority of our lamp columns. Lamp-column powered attachments, Wi-Fi/cameras etc. will be switched off if needed to make safe to work on repairing the lights. Contact phone numbers need to be visible on the attachment to contact in these cases.
Lighting Levels
Lighting levels should be chosen to suit the needs of the user and the environment. Westminster’s streets are often mixed use, so the light from the lanterns needs to provide good lighting for traffic and a safe, secure feeling and a good ambience for pedestrians, cyclists, and other public realm users.
Inadequate lighting prevents and discourages use and exploration of the city, increasing our sense of unease. Conversely, too much uncontrolled lighting creates visual overload, and can negatively impact on amenity and the environment.
It is possible to make accurate predictions of the potential lighting effects and levels of illumination of a scheme (colour, beam angle, light wash, shadow etc.) through the use of illuminated models, sketches and computer modelling.
When designing schemes, thought should be given to the relationship between lighting and paving materials, including the colour and reflectivity of materials. Guidance about pavement materials is provided in the Materials section of this SPD.
Lighting Levels Guidance
A. Streetlights must be designed to avoid direct sky illumination.
B. In-ground uplighters are prone to water damage and difficult to keep clean and maintain and will, in most cases, not be supported. Above ground highway infrastructure are preferred for feature lighting to give a similar effect if required
C. Any lighting should adhere to the Institute of Lighting Professionals Guidance Note 01: The Reduction of Obtrusive Light for the city’s E2-E4 environment zones, curfew time taken as 11pm unless otherwise agreed with Planning.
D. Lighting levels must reflect their purpose and setting, and the level of lighting required to match the activities being undertaken.
E. The Westminster Lighting Design Guide 2020, section 4.2.2 Adaptive Lighting Strategy provides the recommended lighting level and environment zone for every road in the City to advise the right light at the right time with the right controls in place.
Accessibility
Lighting for Accessibility Guidance
A. Light sources which give colour rendering similar to daylight (such as LED lighting) are likely to be of most benefit to people with a visual impairment.
B. Particular care is required at ramps and steps to avoid disguising the gradient or the distinction between steps and risers.
C. BS8300 advises specific minimum lighting levels
D. Trees planted within close proximity to streetlights can create areas of shadow and also cause damage to the lighting
E. The lighting design guide on the Westminster City Council webpage provides a defined hierarchy of streets and spaces, each to be reinforced by specific lighting treatments and a hierarchy of lighting levels. For more information, please see the City of Westminster Lighting Design Guide
Gas Lighting / Electrification / LEDs
At the present time, existing gas lighting assets cannot be adapted. Preserving the listed gas assets is important and no changes to their location or appearance shall be permitted without undertaking a Listed Building Consent process with statutory bodies
A review is currently ongoing with Historic England and Planning regarding unlisted gas lighting assets. Where warranted, due to poor lighting levels with high crime and safety concerns, additional complementary gas effect LED lighting on gas lit roads is available that mimic the appearance of the gas lights, as an addition to the existing listed gas lights.
LED lights are more energy efficient than traditional bulbs, offering 50-80% energy savings. They also have a much longer life cycle than traditional lamps 80, and offer a wider range of colours and brightness – both of which can be controlled remotely, in response to user needs. They are also significantly cheaper to operate. The ability to focus LED lights also results in less upward light pollution.
As new lighting technologies are identified, highway street lighting will look into them to improve the night-time environment and reduce energy and carbon emissions.
Remote Monitoring and Control
Remote monitoring is used to adapt light levels to changing vehicle and pedestrian volumes and other requirements.
This may include the use of smart devices on our assets to provide real time data to assist and improve our services, for example, informing proactive maintenance.
Remote control of lighting assets enables the City Council to control lighting levels in response to how busy a street is at different times throughout the night, and to increase lighting where appropriate for events, or to assist the emergency services.
The central management systems can also be also used to automatically advise of potential power faults or lantern failures, creating jobs on the council’s asset inventory system to enable repairs.
Lighting for orientation, feature and events lighting
Specific guidance on the below is set out in the City Council’s Lighting Masterplan 2020-2040:
• Feature and orientation lighting
• Lighting for retail
• Architectural / Urban realm enhancement lighting
• Lighting of open spaces
• Lighting art/festivals/events
Events and Market Trader Power Supplies
Power supplies can enhance the functionality of public spaces, provide vital infrastructure for street markets and individual trading pitches, and provide energy for temporary, one-off, and seasonal events.
80 https://www.centreforlondon.org/reader/lighting-london/chapter-2-designing-and-managing-lighting/#public-lighting
Different supply wattages are available which must be designed specifically for each site according to site constraints. The City Council have standard options for both virtual metering up to 16 A installations, and standard metered supplies up to 100 A. 16 A is the preferred supply.
16A is universally preferred for isolated pitches, street markets and events, as this allows virtual metering, which is more accurate to the user for paying energy, safer on the highway not having that much power accessible to the public and can be installed at much quicker and cheaper cost. This will also produce much less carbon emissions as per our climate emergency.
Costs and timeframes are specific to the location and different metering types, but 100 A metered supplies can take a minimum of 6 months to install due to the type of work required from the power companies.
Proposals to provide power supplies should take account of the location of underground vaults, cellars, trees, depth of underground tube lines and existing services. Utility companies should be approached for details of their services at the outset of the design.
Approval from respective Events or Market Trader teams will be required prior to starting design for power supply installations.
Ownership of meters needs to be clearly defined and ongoing maintenance, both reactive repairs and routine electrical and structural testing, needs to be undertaken by competently trained persons approved by the council to work on the highway, with their costs covered
Specific guidance on the types of supplies and requirements to follow can be found in in the Market Traders Electrical Supply Guidance. Any overloaded power supplies resulting in work will be at the expense of those who caused the damage. Early and regular communication with traders is needed to keep everyone aware of power limitations
Events and Market Trader Power Supplies Guidance
A. Power connections must be safe, fit for purpose, energy efficient, and not cause any danger or obstruction to other users of the public realm (or anyone else).
B. Cables should not be placed on or across surfaces used by pedestrians and other highway users
C. Third party lighting on or within the highway will be resisted
D. Market trader power supplies will be limited to 16AMP per trader from one power source to provide consistent, managed and safe power supply.
For more information, please refer to the following:
• Chapter 4.5 Street Furniture Guidance in this SPD re: Placement of Wi-Fi and Smart technology and the lighting of street furniture
• Chapter 4.11 Services and Utilities Guidance in this SPD
• Chapter 4.7 Street Trading / Commercial Activity (including Tables and Chairs) in this SPD
Lighting and Trees
Trees planted close to streetlights can create areas of shadow and cause damage to the lamp column due to branch movement and residue deposits and may impact on the health of the tree
Lighting and Trees Guidance
A. Lighting should be positioned away from trees to avoid interference with street lighting performance and permit unobstructed illumination of the carriageway and footway.
B. Positioning advised in the Lighting Design guide, preferably opposite each other or mid-distance between columns, with a minimum distance of 5m between lights and trees such that canopies do not adversely affect lighting performance or lights do not affect tree growth and root system. If the tree type or column type is proven to not affect the other, a reduced minimum distance may be possible once approved by the council.
C. Where trees and street lighting are to be co-located, early consultation with the Westminster Public Lighting and Arboriculture officers must be so that the requirements of both can be considered.
Figure 66: Relationship of trees and street lights, including spacing.
The Westminster Lighting Design Guide provides information on the relationship of trees and street lights, including spacing.
Lighting of Trees
Feature Lighting of Trees Guidance
A. Lighting specifically of trees should only ever be used on exceptional specimens or in exceptional locations - as an integral part of a purposeful place-making scheme. It can cause problems for the tree’s health, light pollution, and increased maintenance requirements, and also raises issues of sustainability in the consumption of electricity and carbon emissions, for a non-essential purpose
B. Commuted sums would be required to allow these, however they are usually not be supported
C. In the limited cases where lighting is deemed to be appropriate, the appearance of lights should not detract from the appearance of the trees or townscape, including the appearance of the lights when they are switched off, nor should they negatively affect local flora and fauna. The amount of hardware required should be minimised, and invasive fixings should be avoided. Installations should always be time limited.
D. The following details will be required before approval by is given:
• Lighting design and specification
• Detailed method statement for installation and removal of lights
• Duration of proposed installation
• Fully costed and funded maintenance schedule, and energy consumption costs
• Risk assessment to include risks to the tree, the public, the installation contractors, and the Council’s tree contractors should they need to carry out urgent work to the tree.
In addition, separate approvals are likely to be required for a highway licence and for electrical source. Advertisement consent may also be required in some cases.
Links and Related Documents and Strategies
• Westminster’s Lighting Master Plan 2020-2040
• Westminster’s Lighting Design Guide
References
• WCC Infrastructure Delivery Plan (IDP)
• Guide to Highway Electrical Street Furniture The Institution of Engineering and Technology 2018