Smart Lighting for UK Commercial Buildings: What It Adds to an LED System You Already Have

By Alistair Brown, CEO of LumenStream, and Chris Anderson, Technical Lead at LumenStream.

Last updated: 28 August 2026

An LED upgrade cuts what each fitting uses. Controls cut how long the fittings run.

The largest review of the evidence is 88 published sources collected by Lawrence Berkeley National Laboratory in 2011. It puts the average saving from occupancy sensors at a further 24% of lighting energy, and from daylight-linked dimming at 28%. In England, Part L expects controls on most lighting refurbishments.

Since the very beginning of LumenStream, we’ve been obsessed with the idea of smart lighting: being able to control and adjust it in an energy efficient way that saved money, generated more energy savings, and, if we’re honest, was simply cool.

And with Chris Anderson joining the team in early 2026, it seems we’ve got the right expertise to make this a reality for more of our customers.

But smart LED lighting is still something many either don’t know about or are cautious about due to its complexity and cost. So, let’s talk about it.

This article covers:

What controls do

What they save

What the regulations ask for

When they're not worth investing in

How to fund them without large upfront capital

It's written for the person who signs off the spend.

If your building went to LED years ago and the controls never followed, this one is for you.

What is smart lighting, and how is it different from the LED upgrade you already did?

Smart lighting means fittings that switch, dim and schedule themselves in response to occupancy, daylight and the clock. The LED upgrade changed the fitting. Controls change its hours.

Swapping old fittings for LED cuts the watts. It doesn't touch the aisle nobody walked down today. Or the row of fittings beside a rooflight burning at full output in June. Or a warehouse lit to full brightness at three in the morning.

Those are runtime problems. Only controls reach them. It's the difference between a more efficient boiler and a thermostat.

The UK trade term is "lighting controls". "Smart lighting" is the same thing in plainer words, and we use both at LumenStream.

Chris Anderson, our technical lead, puts it simply:

"If you go into a warehouse without smart controls, you would just have the whole warehouse lit or illuminated, and it's just a waste of energy."

What are the main types of lighting control?

Depending on how you define it, how much experience you have, and how much you nerd out about LED lighting (and we do a lot), you could group smart lighting into 5 types:

1. Occupancy and presence detection. A sensor holds the light at full output while someone is there, drops it to a low level after a set delay, then switches off after a second delay. The dimmed middle step is called corridor function. You've met it in a car park stairwell that sits dim until you walk in. Two sensor types dominate: passive infrared, which reads body heat and movement, and microwave, which covers more ground and sees through glass.
2. Daylight-linked dimming, also called daylight harvesting. A sensor reads the daylight entering the space and dims each fitting to match. Beside a loading door, the first fitting may sit off, the next at 10%, the next at 20%. It follows the seasons on its own.
3. Zoning and addressable control. Each fitting or group sits on the network, so walking into aisle three lights aisle three rather than the whole floor.
4. Scheduling, scenes and remote access. Lights follow a calendar instead of a switch: on for the shift, off at the end, one preset for a presentation and another for the cleaners. Add a gateway and settings change remotely. Chris once re-timed the lighting on a site four hours away, over a tablet, during the phone call that reported the problem.
5. Colour temperature control, sold as human-centric or circadian lighting. The same fitting runs warm at 2700K and daylight-white at 6500K.

Most buildings need two or three to begin with.

We already have LED. What does adding controls actually save?

Expect a further 24% of lighting energy from occupancy control, or 28% from daylight-linked dimming.

Those come from the Berkeley meta-analysis of 240 savings estimates across 88 published sources, from 2011. The same review puts zone tuning at 36%, and every strategy combined at 38%. That 38% is the ceiling, which is why the individual figures can't be stacked.

Three conditions come with those numbers:

1. They measure lighting energy, not your electricity bill.
2. They average US buildings of every type.
3. Daylight simulations overstate what buildings deliver. The same study found 48% predicted against 28% measured.

You can sanity-check this before anyone quotes you. Take the hours your lights are on, then ask how many of them are spent lighting space with nobody in it.

Gordon Lowry at London South Bank University adds a 4th condition. He reviewed this literature in 2016 and argued that savings get inflated by measuring against a building where the lights were assumed on all day. If your site already switches off reliably, controls have less to reclaim.

What any of it is worth depends on how much of your electricity is lighting, and that swings hard by building type. On 2024 government figures, lighting is 39.0% of electricity in storage and warehousing, 29.9% in education, 27.6% in retail, 20.3% in health, and 15.5% in offices.

A warehouse and an office aren't the same case. And if the fittings themselves are the tired part rather than the runtime, that's a different job, which we covered in We Already Have LEDs.

Which brings us to a natural next question you might be asking…

Do UK building regulations require lighting controls or is it a nice-to-have?

In England, yes, it’s required when you do building work, and it catches more refurbishments than most estates teams expect.

Approved Document L Volume 2 has been in force since 15 June 2022. Paragraph 6.63 covers unoccupied spaces. They "should have automatic controls to turn the general lighting off when the space is not in use". Occupied spaces should have automatic controls where these suit how the space is used. Paragraph 6.64 requires daylight controls where a space gets high levels of natural light.

This is statutory guidance rather than the requirement itself, and it applies to building work rather than to a building left alone. If you're refurbishing, extending or replacing an installation, it reaches you.

Two points most buildings miss:

1. The regulations put a number on what controls are worth. The compliance calculation applies a factor of 0.8 where lights switch off within 20 minutes of a room emptying, and another 0.8 where they dim to daylight within six metres of a window wall. That's the government crediting each control type with a fifth of the lighting energy.
2. There's a rule for larger buildings. In an existing building over 1,000 square metres, installing a fixed building service can trigger consequential improvements. That means energy-efficiency work worth at least 10% of the main job.

Scotland, Wales and Northern Ireland run their own set of rules. Northern Ireland's Technical Booklet F2 lists upgrading lighting below 40 lamp lumens per circuit watt, across more than 100 square metres, as a qualifying measure.

And a new edition of Approved Document L takes effect on 24 March 2027, moving these clauses and adding occupancy or key-card control in hotel bedrooms.

When is smart lighting not worth it?

Controls are a poor investment in four common situations.

1. The space is occupied all day. A sensor only saves where there's a vacancy to find. On one hospital project the corridors stayed on continuous lighting and detection went into treatment rooms only, because the corridors never emptied.
2. Your site already switches off reliably. This is Lowry's point. If the shift routine kills the lights, automation is buying a habit you have.
3. Little daylight reaches the space. Daylight dimming needs daylight. In a windowless interior it's cost with nothing to harvest.
4. The lease is nearly up. A payback counted in years needs years behind it.

If your site is one of those four, we'd rather tell you at the survey than after the quote.

There's also an uncommon fifth case. If the number you're quoted has no baseline, no building type and no source year, it’s likely just marketing. Ask for all three before you take the number seriously.

Even where the case is sound, the project can still disappoint, and the reason is usually the same one.

Why do lighting controls fail after installation?

Because they get commissioned badly, and almost nobody checks.

Innovate UK studied 50 non-domestic buildings after they were occupied. Its 2016 report was blunt: "Lighting systems are often not adjusted properly during commissioning... Commissioning should not be signed off unless lighting controls are seen to work properly."

At Brine Leas School, presence detection and daylight dimming together left corridor lighting on constantly, because presence anywhere in the building triggered it. The atrium had no separate override, so staff could not switch those lights off at all.

At Loxford School in Ilford, every common area sat in one control zone. Well-daylit corridors lit up whenever anything else did.

One school pulled its corridor sensors out after staff complained they were oversensitive. In another building the dimming worked perfectly well, and nobody had been told about it.

Every one of those traces back to zone design, delay settings, override provision or handover.

People turn off a system that annoys them. After that it saves nothing at all.

What does it cost, and how do you pay for it if the capital budget is gone?

Every LumenStream project starts from the same system: new LED fittings with occupancy sensors, and daylight dimming wherever the space gets natural light. That’s current best practice, and Part L expects it on most refurbishments anyway, so we don't offer a version without it.

On top of the standard system there is one optional step.

A smart-enabled system puts every fitting on a network. Zoning, scheduling, scenes and remote access, changed from a tablet instead of a wall switch. It suits large or multi-site estates that will use what it can do. In a small office that switches off at six, it might be money spent on an app nobody opens. Our own office is one of those.

The smart-enabled system earns its place through scale. The extra saving comes from zoning and scheduling, and those pay back in a warehouse running three shifts across twenty aisles. A two-room office has nothing for them to schedule.

Either way, under Lighting-as-a-Service the upgrade carries no upfront cost. You pay one fixed monthly fee, funded by the energy the new system saves, and the capital stays available for the work that has no payback attached.

The only thing to be mindful of is that it only works where the savings are large enough to cover the fee. That's why we survey and model a site before quoting. Where the numbers don't clear, we say so. For how the funding model works in full, see What is Lighting as a Service?

What should you check before signing off a controls specification?

Most controls projects are lost at the specification stage.

Every failure in the Innovate UK sample traces back to a decision taken, or skipped, before an installer arrived. How the zones were drawn, what the delays were set to, whether anyone could override the system, and who’d check it worked: none of those needs a lighting engineer. They need the person signing off to ask six specific questions, and to refuse to accept weak unspecific answers to them.

Those questions:

1. Can every automated area still be overridden by hand? BREEAM won't accept presence detection as occupant control without a manual override, and it's the first thing building users ask for.
2. Who commissions it, and does sign-off depend on the controls being seen to work? Innovate UK found this step gets skipped. Make it a condition of acceptance.
3. What are the delays set to, and who can change them later? Part L only credits controls that switch off within 20 minutes. A delay set too long erases the saving quietly.
4. How were the zones drawn, and did anyone walk the building first? Both school failures above were zoning decisions taken on a drawing.
5. Can settings be changed without a site visit? If not, every future adjustment carries a call-out and a wait.
6. What happens when someone says the lighting is annoying? If there's no answer, you've bought the failure that stripped the sensors out of that school corridor.

We encourage you to ask the vendor all six, including us.

The answer to the second question determines where the money sits. For example, a survey and a model on your own numbers come before any quote we give. Commissioning is signed off only once the controls have been seen working, zone by zone, with the delays set to the agreed values.

If a supplier can't answer all six in writing, walk away from the quote whatever the price.