Warehouse and industrial hall lighting: planning an LED retrofit properly

Key facts in brief: For halls and warehouses, EN 12464-1:2021 specifies maintained values, for example 100 lx for storage rooms, 150 lx for manned aisles in high-bay warehouses, 200 lx for loading and unloading areas and 300 lx for dispatch and packing. A good LED retrofit designs to these values with a realistic maintenance factor, takes vertical illuminance on racks into account and uses presence and daylight control.

Normative basis

EN 12464-1 in the 2021-11 edition governs the lighting of indoor workplaces. For storage rooms and logistics it contains separate tables with maintained illuminance Ēm, uniformity U₀, colour rendering Ra and glare limit R_UGL ^[1]. Compared with 2011, two values have changed: store rooms from 100 to 200 lx, rack storage/rack face from 200 to 75 lx ^[2]^[3].

Area (examples)	Maintained illuminance Ēm
Store and stock rooms	100 lx
High-bay warehouse, unmanned aisles	20 lx
High-bay warehouse, manned aisles	150 lx
Unloading and loading areas	200 lx
Dispatch, packing	300 lx
Storeroom (logistics and warehouse)	200 lx ^[3]

Values according to EN 12464-1:2021; for the specific project, the complete tables and requirements of the standard apply ^[1].

A minimum value is not the same as good light

The standard values are minimum requirements; they may be increased via so-called context modifiers, for example for difficult visual tasks ^[3]. licht.de generally considers 100 lx for storage rooms and 200 lx for open stores to be too little and recommends 300 lx at least in certain areas so that labels and delivery notes can be read easily ^[4]. In rack storage, vertical illuminance is particularly important: only then can labels on all levels be read quickly and without errors ^[4].

Setting the maintenance factor correctly

The maintained value must never be undercut over the entire operating life; therefore maintained value = maintenance factor × initial value ^[5]. In dusty halls, at high ambient temperatures or with infrequent cleaning, the maintenance factor must be set lower. We record the maintenance schedule in the design; the operator is responsible for complying with it.

The maintenance factor is made up of MF = LSF × LLMF × LMF × RSMF, i.e. the lamp survival and lumen maintenance factors of the light source, the luminaire maintenance factor and the room surface maintenance factor ^[5]. If the operating conditions are not precisely known at the design stage, 0.67 is assumed for clean rooms and as low as 0.5 for dirty rooms with a three-year maintenance interval; for modern LED luminaires in lightly soiled rooms with annual cleaning, 0.8 can be chosen ^[7]. The protection rating has a direct effect: in a normal environment with annual cleaning, the luminaire maintenance factor of an IP50 luminaire is 0.90, that of an IP20 luminaire only 0.82 ^[5].

Workplace regulations

In addition to EN 12464-1, the requirements of the German Technical Rule for Workplaces ASR A3.4 must be observed for workplaces in Germany ^[2]. We check both sets of rules and document which value is decisive in each case.

Retrofit procedure

Survey: use, hall height, racking layout, existing luminaires and operating hours
Lighting calculation with variants (luminaire type, optics, grid)
Economic viability: energy and maintenance costs, payback
Controls: presence detectors per aisle, daylight control at rooflights
Manufacturer-neutral tender and acceptance with verification measurement

Funding

In Germany, municipalities and municipal companies can obtain funding for indoor and hall lighting via the Kommunalrichtlinie ^[6]. For businesses, further federal and state funding is available depending on the programme and timing; we check the current status for each project.

Frequently asked questions

Is a 1:1 replacement of old luminaires with LED sufficient?

Rarely optimal. Without a calculation, the installation often ends up too bright (wasting energy) or too dark (non-compliant). Optics and grid should be redesigned.

How quickly does an LED retrofit pay for itself?

That depends on operating hours, electricity price and the existing installation. We calculate it individually in the economic analysis.

What maintenance factor is realistic for an LED hall?

That depends on soiling, the luminaires' protection rating and the cleaning interval. We determine it for each project from the manufacturer's data and document it in the maintenance schedule.

Sources (in German)

Author: Paul Rostand Ndjeundoun, M.Sc. (Hons), Certified Lighting Expert (LiTG), Registered European Lighting Expert · As of November 2026. Standard values have been carefully researched but do not replace consulting the currently valid edition of the standard.