Is there a legal interval for lux testing?
No UK regulation sets a fixed frequency for measuring workplace light levels. Regulation 8 of the Workplace (Health, Safety and Welfare) Regulations 1992 requires lighting to be suitable and sufficient at all times, and the Management of Health and Safety at Work Regulations 1999 require risk assessments to be reviewed when circumstances change. In practice, that means lux testing should be driven by events that could change the lighting, backed up by a sensible routine cycle.
Emergency escape lighting is different: BS 5266-1:2025 sets out a clear routine of tests, covered below.
Events that should trigger a lux test
1. New build, fit-out or refurbishment
A survey at handover confirms the installed lighting actually delivers the design. Design calculations assume particular luminaires, positions, ceiling heights and surface reflectances. A change of supplier, a darker carpet or a relocated partition can all push results below target. Testing before you sign off the fit-out puts responsibility for any shortfall where it belongs.
2. LED retrofit or lighting upgrade
LED upgrades are the most common cause of new compliance problems we see. Replacement fittings are often chosen on wattage or lumens alone, without checking beam distribution, glare rating or spacing. The result can be bright patches directly under fittings and dark areas in between, so the average looks acceptable while uniformity fails. Measure before and after any retrofit. See can an LED upgrade reduce compliance?
3. Change of use or layout
If a storage area becomes a packing area, the target in BS EN 12464-1:2021 rises from 100 lux to 300 lux. Turning a meeting room into desk space, adding high racking, installing mezzanines or moving workstations under a different part of the grid all change what the lighting needs to deliver. Re-test any area where the task has changed.
4. Staff complaints, accidents or near misses
Complaints of eyestrain, headaches, glare or “gloomy” areas are a direct prompt to investigate. So is any slip, trip, fall or vehicle incident where visibility may have played a part. A measured survey turns subjective complaints into evidence and shows whether action is needed. Our guide to why employees complain about lighting covers the usual causes.
5. Risk assessment review
When your general or display screen equipment risk assessment is reviewed, lighting should be reviewed with it. Measured results from a recent survey are the simplest way to evidence that section of the assessment.
6. Insurance, leases and dilapidations
Insurers may ask for evidence of adequate lighting after a claim or at renewal, particularly for warehouses and industrial premises. Landlords and tenants use lux surveys to record the condition of lighting at the start and end of a lease, which avoids disputes over dilapidations.
7. Licensing and inspections
Premises licence conditions, Ofsted or CQC visits, and local authority inspections can all raise lighting questions. Having a current survey on file avoids last-minute testing.
A sensible routine cycle
Even without any trigger, light output declines. Lamps lose output with age, luminaires collect dirt, and decorated surfaces darken. That is why BS EN 12464-1:2021 values are expressed as maintained illuminance: the level the installation must still achieve at the end of its maintenance cycle.
| Premises type | Suggested routine re-test | Why |
|---|---|---|
| Offices and retail | Every 3 to 5 years, or at any layout change | Relatively clean environments, frequent reconfiguration |
| Warehouses and logistics | Every 2 to 3 years | Dust, high bays, racking changes and vehicle risk |
| Factories and industrial | Every 1 to 2 years | Dirt build-up, heat, vibration and higher-risk tasks |
| Schools and healthcare | Every 3 years, or at refurbishment | Vulnerable occupants and inspection scrutiny |
| Car parks and external areas | Every 2 to 3 years | Weather, dirt and vandalism reduce output |
These are good-practice suggestions, not statutory intervals. Dirtier environments and older installations justify shorter cycles. Many clients align lux testing with their electrical inspection cycle or lighting maintenance programme so that cleaning and relamping happen before measurement.
Emergency lighting: a defined routine
Emergency escape lighting falls under the Regulatory Reform (Fire Safety) Order 2005, and BS 5266-1:2025 is the UK code of practice. The routine is more prescriptive than for general lighting:
- Monthly: a short functional test of every emergency luminaire and exit sign, interrupting the mains supply briefly to check each one lights.
- Annually: a full rated duration test, usually 3 hours, to confirm every luminaire stays lit for the whole period, carried out by a competent person.
- Periodically: BS 5266-1:2025 also recommends verifying photometric performance, meaning measured lux levels on escape routes and open areas against BS EN 1838:2024, and checking the system still suits the building layout. Older guidance commonly described this as a three-yearly verification. Check the interval in your fire risk assessment against the current edition.
A monthly flick test proves a fitting works. It does not prove that the escape route receives at least 1 lux along its centre line, or that open areas meet the anti-panic requirement. Only a photometric survey does that. See emergency lighting lux levels and our emergency lighting lux survey.
What to keep on file
- The latest lux survey report, with dates, meter calibration and floor plans.
- Any remedial actions and the re-test results that closed them out.
- The emergency lighting log book with monthly and annual test records.
- A note in your risk assessment of when lighting will next be reviewed.
Schedule your next lux test
Polarity Lux carries out event-driven and routine lux testing across London, Kent, Essex, Surrey, Hertfordshire and the wider South East. Fixed prices start from £90 for a spot check. Book a survey or see how much lux testing costs.
Frequently asked questions
Is annual lux testing a legal requirement?
No. UK law requires workplace lighting to be suitable and sufficient but does not set a testing interval. Testing is expected when something changes, such as a fit-out, LED retrofit, change of use or complaints, plus a routine cycle suited to the premises.
Should I test lighting after an LED upgrade?
Yes. LED retrofits frequently change beam distribution and spacing, which can cause uniformity failures even when the average lux looks fine. Measuring before and after the upgrade confirms compliance.
How often should emergency lighting be tested?
BS 5266-1:2025 recommends a brief functional test every month and a full rated duration test, usually 3 hours, every year. Periodic photometric verification of escape route lux levels is also recommended.
Does a monthly emergency lighting test check lux levels?
No. The monthly test only confirms each fitting lights. Measuring whether escape routes and open areas achieve the minimum lux required by BS EN 1838:2024 needs a separate photometric survey.