Who Connects the Power for an Electric Rooflight?

An electric rooflight has two wiring worlds either side of a small control unit, and it helps to see them as separate jobs before anyone picks up a screwdriver. On one side sits the rooflight itself: the actuator arm or chain drive built into the frame, a rain sensor on the glass, and sometimes a wind sensor, all wired back to a low-voltage control box. On the other side sits the house: the ring main, a consumer unit, and whatever spare capacity your electrics have. The control unit is where those two worlds meet.

We take responsibility for everything on the rooflight side: the unit itself, the actuator, the sensors, and the low-voltage cable run back to the control box, usually tucked against a rafter or inside a loft void where it stays out of the room's sightline. How the actuator and controls work together covers that side of the job in more detail.

The step from the control unit to your household mains is electrical work in the legal sense, whatever trade happens to be holding the cable. In England and Wales, that connection falls under Part P of the Building Regulations, which treats new circuits and fixed wiring in kitchens, bathrooms and similar rooms as notifiable. A qualified electrician makes that final link, tests it, and issues the paperwork that goes with it. We arrange this as part of the job rather than leaving you to find someone separately, and where the work is notifiable, we handle telling Building Control, the same as we do for the structural opening in the roof.

This split is not about who is more capable of pushing a cable through a joist. It is about where legal responsibility sits. A rooflight installer who is not a qualified electrician has no business signing off a mains connection, and a good one will say so rather than quietly doing it anyway.

The load itself is small. An actuator draws power in short bursts, when it is opening, closing or holding position against wind, and sits idle the rest of the time. Some homes run this from the mains through a small transformer built into the control unit; others run it from a battery pack topped up by mains or a solar panel on the roof. Powering an electric rooflight: mains, solar or battery sets out how those three options compare, but whichever you choose, a mains-fed transformer or charger still needs that same notifiable connection at the wall.

Before anyone opens the roof, we agree where the control unit will sit and where the mains feed will come from. A loft conversion with a new consumer unit circuit is straightforward; the electrician can run a fused spur to the exact spot during the same phase of work. An older extension or an existing loft with no spare capacity takes more thought, and sometimes a small addition to the consumer unit itself. Either way, this is a conversation we have at survey stage, not something discovered halfway through the job with the roof already open.

The control unit's position also matters for the room, not just the wiring. It should sit somewhere reachable if a fuse needs checking, but it does not need to be visible from where you sit or lie, and we plan it clear of the sightline your sketch shows. Does an electric rooflight need a wall switch? covers where the day-to-day control point usually goes instead.

Plenty of loft conversions and kitchen extensions already carry a spare fused spur left over from a previous job, an unused socket circuit, or capacity the original electrician allowed for. Where that exists, the electrical side of an electric rooflight can be a short piece of work: testing the existing supply, running a short extension to the control unit, and certifying it. Where nothing exists, it is a slightly longer job, but neither changes how the rooflight itself is fitted or how it looks once it is in.

This is also where remotes and smart home links come into the picture, since a rooflight wired to a smart hub or a home automation system needs its network connection agreed at the same time as its power, not added afterwards.

Because the electrician's connection is separate from the rooflight's own low-voltage circuit, a mains fault at the consumer unit and a fault at the actuator behave differently, and it is worth knowing which is which. Will an electric rooflight close if the power goes off? explains the battery backup most control units carry for exactly this reason, so a lost supply does not leave a rooflight open in the rain.

None of this changes the answer to who connects what. The rooflight, its sensors and its low-voltage wiring are our responsibility from survey to handover. The mains connection that feeds the control unit is a qualified electrician's job, arranged as part of the same install, notified to Building Control where the work requires it, and finished before we call the job complete. Every quote also comes with a sightline sketch, so you can see how the frame, the control unit and the sky line up in the room before any of this wiring goes in; see the sightline sketch for how that drawing is made. For how an electric unit compares with a manual one on price, what affects the cost of a rooflight sets out the general ranges.

Do I need to arrange the electrician myself?

No. We arrange the electrical connection as part of the job, so you are not left coordinating two separate trades or two separate visits around the same hole in your roof.

Does the low-voltage wiring inside the rooflight need an electrician too?

No. The wiring between the actuator, the sensors and the control unit is low-voltage work carried out as part of the rooflight installation. Only the connection from that unit to your household mains is notifiable electrical work.

Will I need a new circuit at the consumer unit?

Sometimes, and it depends on what your existing electrics already have spare. We check this at survey stage so it is priced and planned before the roof is opened, not decided on the day.

Can the mains connection be finished before the rooflight is fitted?

The two are usually sequenced together, since the control unit's position depends on the rooflight's final placement. Where a consumer unit upgrade is needed, that part can often be done ahead of the install day.