Electrical
Lighting and emergency lighting design
Interior, exterior and emergency lighting design to BS EN 12464-1:2021 and BS 5266-1:2025, with calculated illuminance, glare and uniformity.
- Discipline
- Electrical
WHAT IT IS
Lighting design establishes what each space needs to be lit to, and then delivers it: luminaire selection, layout, control, and the calculations that demonstrate the criteria are met.
The criteria are not just illuminance. BS EN 12464-1 sets maintained illuminance, uniformity, unified glare rating and colour rendering for the task being performed. A space that meets the lux level and fails the glare rating is uncomfortable to work in, and that shows up as a complaint rather than as a compliance failure.
Emergency lighting is designed alongside it rather than added afterwards — escape routes, open areas and high risk task areas to BS 5266-1:2025, using the same luminaire layout where a combined fitting will do the job. It has its own page, covering the design in detail.
IN DETAIL
Covered in more detail
Emergency lighting design
Emergency escape lighting design to BS 5266-1:2025, covering escape routes, open areas, high risk task areas and testing provision.
WHEN YOU NEED IT
On any new build or fit-out, on any refurbishment where the lighting is being replaced, and on any project with a Part L or Section 6 requirement where lighting efficacy and controls contribute to the compliance calculation.
DELIVERABLES
What you receive
- Lighting calculations with illuminance, uniformity and glare
- Luminaire schedule
- Lighting layouts
- Lighting control strategy and zoning
- Emergency lighting integration
STANDARDS
Standards applied
The editions in force at the time of design. Where a standard is amended mid-project we confirm which edition the appointment is based on.
- BS EN 12464-1:2021Lighting of work places — indoor work placesBSI
- BS EN 12464-2:2014Lighting of work places — outdoor work placesBSI
- BS 5266-1:2025Emergency lighting — code of practice for the emergency lighting of premisesBSI
- SLL Lighting Guide 7OfficesSLL
- SLL Code for LightingSociety of Light and LightingSLL
- Approved Document LConservation of fuel and power (England)GOV.UK
QUESTIONS
Common questions
What lighting levels are required in an office?
BS EN 12464-1:2021 gives 500 lux maintained on the task area for general office work, with a unified glare rating limit of 19 and a minimum colour rendering index of 80. Surrounding and background areas have lower requirements, and the standard sets uniformity ratios for each.
What is unified glare rating?
Unified glare rating, or UGR, is a calculated measure of discomfort glare from the luminaires in a space, viewed from a defined position and direction. BS EN 12464-1 sets a maximum UGR for each task type — 19 for general office work — and it is calculated as part of the lighting design rather than assessed on site.