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How to comply and exceed Part L of the UK Building Regulations and the Future Building Standards and create transformational lighting designs

Architecture and construction are currently being influenced by rapidly changing technology, design considerations, and social attitudes. Lighting is an important component of these advancements.
Lighting is an important component of these advancements. Modern architectural projects in the commercial, residential, hospitality, education, healthcare and industrial sectors have all adopted LED lighting as a mainstay.
However, the future of LED lighting must be considered. What impact will building codes have on their use and specification? What impact and transformation will LED lighting have on interior designs?
From our studio in St John’s Square London, Detail Lighting has been involved in many London based fit-out projects. These include residential lighting, hospitality lighting and landscape lighting.
how to comply and exceed part l of the UK building regulations in a hotel

Overview and key criteria of Approved Document L - L1A, L1B, L2A and L2B

Approved Document L of the Building Regulations establish specific requirements for the design and construction of buildings.
“Where a building is erected, it shall not exceed the target CO2 emission rate for the building…”, according to Regulation 26 of the building regulations, and Schedule 1 – Part L Conservation of fuel and power states that “provision for fuel and power conservation shall be made by:
– limiting heat gain and losses and providing building services that are efficient
– have effective controls, and are properly commissioned
– and that information is provided so that the building can be operated efficiently

What are the key points of Part L and how do you comply with your lighting?

The best way to understand Approved Document L is to divide it into two parts: L1A and L1B, which deal with dwellings, and L2A and L2B, which deal with buildings other than dwellings.
At least 75% of fixed internal light fittings in new residences (document L1A) must have a minimum of 45 lamp lumens per watt (their output should be greater than 400 lamp lumens in total, to count).
Table and bedroom lights, as well as light fittings under 5 watts, are examples of non-fixed products that can be excluded.
For fixed lighting in external conditions, in new dwellings, it must be either:
– under 100 watts and automatically regulated using a light sensor to turn them off when daylight is sufficient
– or have a lamp efficacy greater than 45 lumens per Watt, and again controlled with a light sensor
Existing dwellings (document L1B) are normally exempt, with the exception of newly constructed or refurbished portions of a structure, such as additions, conversions, or renovations. However, this isn’t always the case, and a local building control officer should always be consulted.
The documents L2A and L2B refer to new and existing buildings other than homes, which include spaces with a greater footfall and so require additional requirements.
how to comply and exceed part l in retail
Pictured above: Cortes 48v LED System by Detail Lighting – a low voltage track system controlled with DALI driver, available with surface or trimmed recessed options.

In terms of L2A, this section of the regulations distinguishes between luminaire lumens and lamp lumens. It’s important to remember that luminaires aren’t 100% efficient, and the reflector, diffuser, or lamp shade absorbs or blocks some of the light.

Luminaire lumens is the level of light produced by a fitting after you take into account the light that’s lost through absorption by the reflector, diffuser or shade.

This is an important consideration because even the most energy-efficient light bulbs might lose efficiency and energy if they are fitted with a certain material as a shade or diffuser.

This has an impact on your lighting designs as you must determine whether to include LED lighting without decorative shades in your lighting systems, which is typically recessed lighting. If you wish to use more decorative lighting designs, material choice, overall design, and diffuser shape/size are all important factors in lighting efficiency.

In order for lighting schemes in office, industrial, and storage facilities to comply with papers L2A and L2B, the sum of all general light fittings must average 60 luminaire lumens per circuit watt.

The sum of all fittings in lighting designs for commercial, hotel, educational, healthcare, and other sectors should have an average efficacy of 60 lamp lumens per watt. It’s 22 lamp lumens per watt for a higher show lighting setting.

The conditions in Document L2B for existing buildings other than homes are similar to those in Document L1B, which applies to newly enlarged, refurbished, or rebuilt areas.

But, is the above-mentioned criteria, however, still relevant in today’s world? Should rules be toughened to reflect the growing desire for a carbon-free world.

Overview and key criteria of Future Building Standards

The Future Building Standards are a significant update in building laws that embody the industry’s low and zero carbon objectives, with non-domestic buildings becoming greener and more energy efficient.

Many local governments believe the requirements in Approved Document L fall behind other industry norms, according to reports. The latest major change occurred in 2013, and since then, with the widespread use of LED technology, lighting has become considerably more advanced, and you could argue more capable of energy savings.

The Future Homes Standard has established a clear goal of reducing carbon emissions by 75-80% by 2025 compared to present standards. Approved Document L, which raises the minimum efficiency standards, will be a part of this.

With some designs having lighting with efficiencies as high as 160, the technology is clearly available now to greatly exceed Part L regulations. However, turning things off or turning them down when they’re not in use is one of the most energy-efficient things you can do. With the adoption and specification of smart building technology and control equipment, this may be accomplished more easily nowadays.

This factor is also taken into account by BREEAM (BRE Environmental Assessment Method), where the category Hea 01 Visual Comfort requires that occupant controls be considered at the design stage for artificial lighting to ensure best practise in visual performance and comfort for building occupants.

With the above in mind, you could argue that meeting the Future Building Standards and the 2025 deadline involves a combination of technological factors, such as available design/technology, and social factors, such as instructing users in an office building to switch off lighting when not in use.

The rising popularity of LENI: Lighting Energy Numerical Indicator

The LENI method provides an alternative way of calculating the lighting energy performance of a building, and together with the Future Building Standards, represents a much-needed shift in philosophy and attitude when specifying lighting.

It encourages the intuitive use of controls and optimum lighting practises to reduce energy usage. Based on kWh/m2/year, this new calculating methodology also reflects much more correctly how a room will be used and illuminated.

The method can be integrated into Approved Document L evaluations, notably for Document L2A and new structures other than homes. LENI values represent complete buildings and can be used to compare the energy consumed with lighting schemes.

how to comply and exceed part L stair case
Pictured above: DALI Simmtronic System was installed and designed in a system with LED lights by Detail Lighting, at the Bow Arts Trust, Grade II listed Pennington Street Warehouse

Creating distinctive and transformational spaces using LED lighting

How will LED lighting continue to transform interior and external environments, given the above facts on how building standards are influencing lighting specification?

The purpose of architectural lighting design is transformational for physical environments and used to improve the user experience, whether this is for working, relaxing or taking part in activities. But the transformational extent is now becoming ever more relevant in the specification and design process.

For example, current and future trends in office designs represent a more ‘resi-mercial’ approach – so adopting more of a residential influence in the commercial environment. This new design trend involves dividing large open-plan areas into smaller, more purposeful sections e.g. desk areas, break out spaces, meeting rooms and storage options.

This separation into several zones will undoubtedly require a more sophisticated lighting approach, which represents a more human-centric design. Human-centric LED lighting solutions aim to create the best possible conditions for the people who use the area while also reducing energy consumption.

This refers not just to the scheme’s colour and layering, but also to the technology that goes with it, as well as the capacity and flexibility to control lighting levels. This is a big benefit and a key aspect in not only complying with existing UK Building Regulations Part L and LENI, but also in the Future Building Standards’ ambition for a net carbon zero society.

The current use of DALI lighting control systems is an example of such a control system. DALI, or Digital Addressable Lights Interface, allows lighting to be controlled more precisely and flexibly via a digital signal. At the Bow Arts Trust, Grade II listed Pennington Street Warehouse, a DALI Simmtronic System was installed, which was developed in a system with LED lights by Detail Lighting.

For more information on creating transformational designs using LED lighting, as well as guidance on how to comply and exceed current and future UK Building Regulations, contact us via telephone 01908 613256 or use our contact form and one of our team will be in touch as soon as we can.

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