Considering updating your business lighting

What makes business lighting energy efficient?

Efficient lighting provides the right amount of useful light, in the right place, for the time it is needed. It combines appropriate equipment with a suitable layout and practical controls.

Using less electricity is valuable, but a scheme that leaves inspection benches in shadow or dazzles drivers in a yard has not met the business’s needs. Start with an agreed standard of lighting, then assess how efficiently different designs can deliver it.

The Carbon Trust’s lighting overview brings together equipment, design and controls as parts of an effective lighting strategy.

1. Start with a lighting survey

Record what is installed, where it is used and how long it runs. Include offices, circulation routes, toilets, stores, workshops, external areas and emergency lighting.

A useful survey should establish:

• The number, type, condition and position of existing fittings.
• The total electrical input of each fitting, including control gear where relevant.
• Operating hours for each area, including cleaning and security routines.
• Existing switches, sensors, timers and dimming arrangements.
• Daylight availability and areas of glare or shadow.
• Maintenance problems, failed lamps and access requirements.
• Staff feedback and any planned changes to the space.

Check assumptions against actual practice. A warehouse may operate for ten hours a day while an individual store cupboard is occupied for only minutes. Using the same hours for every fitting can distort both the baseline and the savings forecast.

Also decide what to do about failed existing lights. Restoring a poorly lit area to an appropriate standard may require more useful light than it currently receives. The proposal should explain this, rather than promise a saving based on leaving inadequate lighting uncorrected.

2. Design the lighting around the tasks

A reception, a computer workstation and a detailed assembly bench do not have identical requirements. Consider the work surface, surrounding area, people moving through the space and how the building is used at different times.

Workplaces must have suitable and sufficient lighting. HSE also highlights the need to assess glare, vehicle movements and the different light levels required for different activities. See its guidance on workplace lighting and lighting and human factors.

For indoor workplace design, BS EN 12464-1 addresses the quantity and quality of illumination. The designer should identify the relevant criteria for your tasks and verify the completed scheme. A general lighting figure for an entire building is not a substitute for that assessment.

Ask for a design that considers light levels, uniformity, glare, colour appearance and the effect of shelves, machinery and partitions. BSI lists the current indoor workplace lighting standard.

3. Compare LED retrofit with replacement fittings

There are two broad approaches: fitting suitable LED lamps into compatible existing equipment, or replacing the complete light fitting, also called the luminaire.

LED lamp or tube retrofit

A compatible retrofit can retain serviceable fittings and reduce initial disruption. It may be worth considering where the existing layout is appropriate and the fittings remain in good condition.

Compatibility needs checking. Fluorescent fittings can use different control gear, and an LED tube is not automatically suitable because it physically fits. The chosen product’s instructions, ballast compatibility, emergency operation and any required modifications must be assessed by a competent electrician. Manufacturer resources such as LEDVANCE’s LED tube guidance illustrate why product specific checks matter.

Complete LED luminaire replacement

New fittings allow the optics, electrical components and controls to be selected together. They may be preferable where old fittings are damaged, yellowed, difficult to maintain or poorly positioned.

Compare both options over their expected use, including installation labour, maintenance access, control compatibility and the lighting result. The lower purchase price does not necessarily give the lower overall cost.

4. Specify useful light rather than wattage alone

Wattage tells you how much electrical power a fitting draws. It does not, on its own, tell you how well that fitting will light a desk, aisle or production line.

Ask the designer to explain the specification in practical terms:

• Lumens: the light output of the fitting.
• Lux: the light reaching the relevant surface.
• Light distribution: how the fitting directs light across the space.
• Glare control: how direct brightness and reflections are managed.
• Colour rendering: how accurately colours can be distinguished.
• Colour temperature: the warm or cool appearance of the light.

In a warehouse, light needs to reach aisles and relevant rack faces. In an office, reflections on screens matter. In retail, products and skin tones may need a different approach from a loading area. Avoid choosing a cooler looking light simply because it appears brighter in a showroom.

Discuss flicker performance, particularly around moving machinery and for people sensitive to lighting effects. For glare, ask for a calculation for the room arrangement; a product labelled with a glare rating does not guarantee that every installation will achieve it. The Society of Light and Lighting publishes technical guidance on glare, temporal lighting effects and LED lifetime metrics.

5. Match the fittings to the environment

The installation needs to suit more than the room dimensions. Discuss dust, moisture, cleaning processes, ambient temperature, impact risk and any corrosive conditions.

A fitting appropriate for an office ceiling may be unsuitable for a cold store, washdown area or dusty workshop. Areas with flammable or explosive atmospheres need a specialist assessment and appropriately selected equipment. CIBSE’s lighting guidance explains why working conditions and the building itself affect the design.

For external lighting, agree the area to be illuminated and consider neighbouring properties, road users, operating hours and wildlife sensitivity. Aim and control the fittings so that useful light reaches the site without unnecessary spill.

6. Add controls that suit the way people work

Efficient fittings can still waste electricity if they run unnecessarily. Review the control strategy at the same time as the lights.

• Occupancy controls: useful for intermittently used areas, with coverage and delay settings matched to activity.
• Daylight linked dimming: reduces electric lighting where daylight can contribute to the required level.
• Timers and schedules: align operation with opening hours, while allowing for cleaning, overtime and security.
• Zoning: lets individual areas operate independently.
• Manual control: gives users an understandable way to respond to changing needs.

Ask what happens if a seated worker makes little movement, shelving blocks a sensor or a staff member enters a dark aisle. Controls should support safe use, and ordinary occupancy switching must not undermine emergency lighting.

Include commissioning and staff instruction in the price. Test detection, delays, daylight response and overrides in realistic conditions. A system that frustrates staff is more likely to be overridden permanently.

7. Calculate the savings using a clear baseline

The basic calculation is:

Annual electricity use in kWh = number of fittings × total watts per fitting ÷ 1,000 × annual operating hours.

Use the complete fitting’s input power, not just the lamp label. Older control gear can add consumption. Use your marginal electricity unit cost for savings, rather than assuming that fixed standing charges will disappear.

A worked example

Suppose a business has 60 older fittings drawing 80 watts each, including control gear. They run for 3,000 hours a year. A proposed replacement design uses 60 fittings at 35 watts each while meeting the agreed lighting requirements.

This represents an illustrative reduction of approximately 56% in the electricity used by those lights, not in the business’s total electricity bill. The tariff and equipment are examples, not a quotation or guarantee.

If the installed project cost were £7,000, energy savings alone would give a simple payback of approximately 3.5 years. This excludes finance, tax, maintenance changes and other effects.

Calculate control savings from the new LED baseline. For example, reducing the equivalent full output hours from 3,000 to 2,400 would reduce the proposed lighting use from 6,300 to 5,040 kWh. That is an additional 1,260 kWh saved, not another percentage applied to the original installation.

8. Compare the full installation and maintenance cost

Check whether quotations include surveys, design calculations, fittings, controls, wiring changes, access equipment, making good, waste handling, testing and handover. High ceilings or restricted working hours can materially affect labour and access costs.

Ask about driver and component availability, warranty exclusions and the labour involved in a warranty replacement. A long advertised operating life does not mean the whole fitting is guaranteed for that period or that it will maintain its initial light output indefinitely.

If existing lights are already LED, identify the remaining opportunity before replacing them. Better controls, cleaning, a revised layout or selective replacements may be more appropriate than changing every fitting.

9. Review emergency lighting separately

Normal lighting and emergency lighting serve different purposes. A brighter general installation does not establish that people can move safely when its supply fails.

Check escape routes, exits, stairs, open areas and any locations identified by the fire risk assessment. Where an existing fitting incorporates emergency equipment, confirm how its replacement will maintain the required function.

The project should include appropriate emergency lighting design, commissioning, documentation and a maintenance and testing regime. BS 5266-1 provides the UK code of practice; the current edition is BS 5266-1:2025. BSI explains its scope in its emergency lighting guidance.

Agree arrangements for keeping escape routes adequately lit during the installation, including any temporary measures needed while circuits are isolated.

10. Plan a safe changeover and responsible disposal

Arrange the installation around trading hours, production schedules and access restrictions. A phased programme can help keep occupied areas usable, but the work still needs safe isolation and clear separation from staff and customers.

Before drilling or disturbing older ceilings and services, provide the contractor with relevant asbestos information. The scope should identify any further checks needed.

Old lamps and fittings need an appropriate waste route. Fluorescent tubes are classified as hazardous waste; they should not be put in general waste or deliberately broken to save space. Agree collection, storage and documentation with the contractor. The Environment Agency’s WEEE classification guidance sets out the relevant lamp categories.

11. Check the finished result and measure performance

At handover, check the installation against the agreed design and assess it in use. Confirm appropriate light levels, uniformity, control operation and emergency functions, with the relevant electrical testing and certification.

Ask staff about glare, shadows and sensor behaviour after they have used the space. Record settings and provide instructions so the scheme can be maintained and adjusted without losing the intended savings.

For larger installations, consider submetering or other suitable measurement. Compare equivalent periods and allow for occupancy and operating hour changes. Whole building bills alone can hide lighting savings when machinery, heating or production demand also changes.

If solar is planned, feed the new lighting demand into the solar assessment. Reducing consumption and generating electricity can work together, but each proposal should use a consistent baseline.

Frequently asked questions

How much can a business save by switching to LED?

It depends on the existing installation, operating hours, replacement design and controls. Ask for a calculation for your premises. A percentage reduction in lighting consumption should not be presented as the same percentage reduction in your whole electricity bill.

Can we keep our existing light fittings?

Sometimes. Their condition, compatibility, emergency function and the quality of the resulting light all need checking. Compare a suitable retrofit with complete replacement before deciding.

Will LED lighting be too bright or harsh?

It should be selected and designed for the space. Discuss glare control, colour appearance and distribution, and consider a sample installation in a representative area before ordering a large quantity.

Do we need to close during the work?

That depends on the layout and scope. Phased or out of hours work may be possible. Agree access, isolation and temporary lighting before the programme is confirmed.

Is there any benefit if we already have LED lighting?

There may be an opportunity through controls, layout changes or targeted replacement, but it needs assessing. Replacing serviceable LED fittings is not automatically the best investment.

Plan your business lighting upgrade with REF Electrics

Whether you are improving an office, shop, warehouse or workshop, start with the way the space is used. REF Electrics can discuss commercial lighting upgrades across Somerset and the South West, helping you consider visibility, operating costs and the practical requirements of the work.

Request a site survey to discuss energy efficient lighting for your business.