Kristina Allison: The four pillars of designing energy effective lighting

Kristina Allison of WSP and the Society of Light and Lighting on how businesses and designers can make smart lighting choices

As both the Environmental, Sustainability and Net Zero Lighting Capability Lead at professional services firm WSP and the President Elect of the Society of Light and Lighting (SLL), Kristina Allison is well-placed to give the ETL her insights on how businesses can save electricity and costs with the right energy efficient lighting.

Kristina Allison, Environmental, Sustainability and Net Zero Lighting Capability Lead at WSP / President Elect of the Society of Light and Lighting (SLL)

According to a UK government study, internal lighting accounts for 26% of commercial buildings’ electrical energy use, making it a crucial area for businesses to cut energy costs and reduce emissions as the UK heads towards Net Zero. While upgrading conventional lighting to LED technology offers substantial energy savings, they’re just one part of a much bigger opportunity to improve lighting performance and long-term efficiency. 

Drawing on her experience in sustainability and design, Kristina outlines what to look for beyond LEDs and how simple changes can lead to long-term savings. Her four pillars of energy effective lighting provide a practical framework to help businesses and designers make informed, future-ready choices that support both Net Zero goals and day-to-day performance. 

The four pillars of energy effective lighting

When considering lighting, Kristina advises purchasers to consider four main elements: the quality, maintenance, efficiency, and controllability of the system. She refers to these as “the four pillars of energy effective lighting”. 

Kristina explains that the first pillar, quality of lighting, goes beyond efficiency to shape how a space feels and functions. “The quality of light is always your primary concern with any installation for it to be a successful installation,” she says. It’s often what people notice first and what they’re most likely to raise concerns about, so it’s essential to strike the right balance between aesthetics, comfort and performance. 

This includes factors like colour temperature, which must be appropriate for the building’s purpose and environment: “You should make sure the lighting isn’t too cool, or too warm, and that it’s appropriate for your environment. For an office, you’ll want to use 4,000 Kelvin, which is mid-white and helps when looking at paper. A 3,000 to 2,700 Kelvin is a warmer white, and that’s better for a more relaxed or cosy environment. In a gym or a busy corridor, a 6,000 Kelvin will work better.” 

The second pillar is the cost of maintenance. Kristina says, “You’ll own the lighting for a long time, so consider how much it will cost to maintain it”. Consider the balance between long-term operational savings and the upfront capital expenditure. While energy efficient lighting might come with a higher initial cost, the savings in maintenance and energy costs over the lifespan of the system can significantly offset this. Making the right investment in quality lighting today can result in substantial financial benefits in the future. 

The third pillar is energy efficiency, which, Kristina stresses, is not isolated but integrates into the holistic design process: “Once you’ve ticked the first two boxes, energy savings should be prioritised.” Energy efficiency needs to integrate into the overall design, balancing quality, maintenance and operational savings. This holistic approach ensures that energy savings are built into the functionality and aesthetics of the space. Kristina also underlines that rising energy costs amplify the need for efficiency in lighting solutions, making this pillar increasingly relevant in commercial decision making. 

Finally, the fourth pillar is controllability. “Can we dim things down? Can we turn them off if we need to? Can we zone things so that certain areas aren’t on or are at a low setting?” Proper implementation of lighting controls like dimming and zoning can enhance energy efficiency while also contributing to a more comfortable and adaptable working environment.

Setting the standards for sustainable lighting design

Building operators, purchasers and facilities management companies must navigate various compliance and reporting requirements related to lighting. These include Part L of the UK Building Regulations, which sets performance standards for lighting and aims to improve energy efficiency in buildings. Part L encourages the use of energy efficient lighting solutions and the integration of lighting controls, aiming to reduce energy consumption while improving overall building performance. 

Meanwhile, the Energy Savings Opportunity Scheme (ESOS) is a mandatory energy assessment scheme for large organisations, requiring energy audits every four years, to identify opportunities for saving energy and reducing costs. Similarly, the Streamlined Energy and Carbon Reporting (SECR) requires qualifying companies to report annually on their energy use, greenhouse gas emissions and actions taken to improve energy efficiency. 

These initiatives should not be seen as just regulatory requirements, as they present a valuable opportunity to unlock long-term energy efficiency, reduce emissions and drive sustainability improvements. Together, these policies form a framework that not only ensures compliance but also supports more informed and sustainable decision-making across building design, operation and maintenance.  

Kristina recommends that building managers, purchasers and facilities management companies first make sure that they have installed LED lighting and then consider what else they can do to ensure greater sustainability with their lighting choices: “Take a look at your lighting equipment and think about how many years it has left. Does it need replacing with LEDs? If you have an up-and-running LED system, then think about what kind of lighting controls can be included.”  

TM65.2 and TM66: Tools for a more sustainable lighting industry

Kristina co-authored and project managed TM65.2 and TM66, two standards that assess the environmental impact of lighting, especially in terms of embodied carbon. The standards are managed by the Chartered Institution of Building Service Engineers (CIBSE).  

TM65.2: Embodied carbon in building services: lighting

TM65.2 provides a methodology for estimating embodied carbon in building services such as lighting systems, focusing on the materials and components used and drawing on data supplied by manufacturers. Kristina explains that the standard addresses a significant gap in the industry: the lack of reliable data around material choices in lighting products, “TM65.2 introduces extended material lists that accurately represent the lighting industry, enabling designers to understand the embodied carbon of their products more effectively.” TM65.2 also draws on case studies from 18 manufacturers to show how different materials influence the carbon footprint of luminaires, helping specifiers make informed, sustainability-focused decisions. 

TM66: Creating a circular economy in the lighting industry

TM66 is a framework that guides the adoption of circular economy principles in lighting design. It encourages professionals to assess products based on their recyclability, modularity, and sustainable sourcing practices. The aim is to improve sustainability in lighting, help designers and purchasers choose more sustainable products, and reduce waste. “TM66 isn’t mandatory, but there’s a global awareness of this approach, and it’s been adopted by manufacturers, designers and consultancies in the UK and Europe.” Kristina says. “In terms of lighting design, TM66 is about making informed decisions about the products that you’re specifying, such as what materials are being used, if any of them are recycled, and whether it was manufactured locally or not.” 

A key aspect of TM66 is its accompanying Circular Economy Assessment Method, a practical tool that rates products on a scale of compliance with circular economy principles. Kristina explains, “At the end of the assessment you come out with a score, which helps you compare products and improve your design.” 

While TM65 and TM66 originated in the UK, their reach is global, with Kristina also consulting with professionals in the US and Australia. Kristina notes how TM66 has been adopted by organisations like National Highways in large-scale projects, demonstrating its applicability across industries: “National Highways adopted TM66, making it a criterion for all products across their projects. This is driving big, meaningful change at a large scale.” 

Kristina reiterates a key theme running throughout her advice: effective lighting design isn’t about prioritising one factor over another.

Lighting designers often face challenges obtaining verified data from manufacturers, particularly advanced metrics like energy data, embodied carbon assessments and circular economy scores. Obtaining this information can often be a time-consuming process. The ETL provides independently verified data and tools, empowering designers to prioritise innovation and sustainability without the administrative burden. 

What to know about lighting controls

When choosing a lighting control system, Kristina emphasises the importance of tailoring the product to the specific needs of your building. She advises against overly complex systems that may exceed functionality requirements, stating, “Building lighting controls can be fantastic in terms of energy savings. The thing here is to choose one that fits your actual needs. You might not require an all-singing, all-dancing one if you simply want to use it for dimming lights and only use 5% of the actual functionality.”  

Kristina further recommends considering how your building’s needs might evolve over time: “You should think ahead, too. What will you need it for in the future, will there be any changes in your building which mean you need one that can do more?”  

To maximise the benefits of lighting control systems, proper commissioning is key. Kristina highlights this by saying, “Be practical, be reasonable, and make sure it’s commissioned properly to ensure the right light levels are set.”

She notes that collaboration between lighting designers and manufacturers is crucial during commissioning to ensure the system meets its intended purpose effectively. 

While lighting controls offer substantial energy savings, they can be difficult to configure effectively without proper commissioning. Collaboration between designers and manufacturers is essential to overcome this challenge. The ETL's inclusion of technical specifications simplifies this process, providing designers with reliable guidelines that help them implement controls tailored to building requirements. 

Kristina points out the common issue of systems being underutilised or incorrectly configured post-installation. “People often don’t know how to use these systems, and that means they can be left on by default, or lights are left on all the time.” Proper training and awareness of system settings can help mitigate these issues and ensure the system delivers its energy-saving potential. 

How Technical Specification and BIM Object files aid designers

Technical Specification files provide crucial information and data such as product name/model number, size/dimensions, performance, electrical data, components, drawings, features, compliance certifications, installation information, and other technical data and specifications. BIM Object files are invaluable for designers and architects as they allow the integration of energy-efficient products into digital designs for buildings and spaces. 

Kristina highlights the importance of Technical Specification files in her work: “The more information, the better,” she says.

By integrating both Technical Specification and BIM Object files, the ETL streamlines the process for manufacturers during the application process. The functionality to add these files is now live and can be added by manufacturers during the application process. You can find out more in our article here. 

How the ETL supports lighting designers

Lighting designers often face challenges in accessing the detailed product information necessary for sustainable designs. Whether it's gathering advanced environmental data, conducting independent verifications, or educating clients about embodied carbon, these obstacles can slow progress and complicate decision-making. 

The ETL has recently enhanced its functionality, allowing manufacturers to upload Technical Specification files and BIM Object files to provide more comprehensive product information. This enhancement helps to streamline the purchasing process, enabling designers to confidently select products that meet client expectations and sustainability standards without compromising on quality or compliance. 

Lighting technologies on the ETL 

The lighting category on the ETL includes three specific sub-technologies:  

• Building Lighting Controls:  This category includes devices that manage lighting systems for greater efficiency, from presence detectors to daylight sensors, enabling lighting designers to create smarter, more flexible systems. By integrating smart controls, such as occupancy sensors and adaptive dimming, businesses can optimize energy use, reduce waste, and extend the lifespan of their lighting systems, leading to both operational savings and improved sustainability outcomes. ​​​​
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• Efficient White Lighting Units: These units offer high-efficiency lighting for various environments, designed to maximise energy savings while delivering optimal brightness and durability. These units provide flexibility and reliability, enabling designers to meet both energy efficiency goals and aesthetic requirements without compromising on performance. 

• White LED Lighting Modules for Backlit Illuminated Signs: Tailored for backlit applications, these LED modules ensure efficient, long-lasting illumination for signs, helping reduce energy costs for continuous or heavy-use lighting. By specifying these modules, designers can create sustainable, cost-effective signage solutions without sacrificing visual impact or durability, making them an ideal choice for both aesthetic and functional lighting designs. 

If you’re a manufacturer of products within these sub-technologies, we strongly encourage you to apply to have your products listed on the ETL. The application process is straightforward, free of charge, and provides valuable exposure within the growing market for energy efficient solutions. By listing your products on the ETL you align your products with industry best practices, gain increased market visibility, and provide impartial verification, which helps build trust and credibility prevents claims of greenwashing. You can browse the Lighting category on the ETL here to review criteria requirements. 

Discover more about how the ETL is supporting the lighting industry navigate new energy efficiency demands in our feature in SSL Light Lines magazine. Read the full article here. 

Have questions?: Reach out to us at info@etl.energysecurity.gov.uk for further information or assistance. 

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