Where the line falls between electrician and fitter
An electric rooflight has two kinds of wiring, and only one of them is mains electrical work that belongs with an electrician.
Most electric opening rooflights run their motor on 24 volts. A control unit, usually a small box fixed in the ceiling void, a loft space or a cupboard near the opening, takes mains power in and sends low voltage out to the actuator, the rain sensor and any wall switch or remote receiver. Everything downstream of that box is extra-low-voltage cabling, much like a doorbell or an alarm keypad. Everything upstream of it is 230V and connects to the circuits in your home.
The upstream part is what the question is really about. Someone has to take a feed from an existing circuit, or run a new one, to a fused connection unit beside the control box. That is electrical installation work under Part P of the Building Regulations in England, and it has to meet the wiring regulations, BS 7671. It should be done by a qualified electrician who can test it and issue a certificate for it.
The downstream part is usually handled by the team fitting the rooflight, because the cable runs through the kerb and upstand they are building and the connections are made to the manufacturer's own plugs and terminals. Our guide to how electric rooflights work explains what each of those components does, and whether electric rooflights are 24V or 230V covers the few models that take mains voltage straight to the motor, where more of the job falls to the electrician.
| Part of the job | Who does it |
|---|---|
| Mains feed and fused spur | Qualified electrician |
| New circuit or consumer unit work | Electrician, notifiable |
| Control unit to motor (24V) | Rooflight fitter |
| Rain sensor and wall switch | Rooflight fitter |
| Solar unit, no mains | No electrician needed |
When the electrical work is notifiable
Not every mains connection has to be reported to Building Control, but every one has to be done properly, and the electrician decides which category your job falls into.
In England, adding a fused spur to an existing ring or radial circuit in an ordinary room is generally minor work that does not need notifying, as long as it is not in a bathroom or other special location. Running a brand new circuit from the consumer unit, or replacing the consumer unit itself, is notifiable. So is almost any new work in a bathroom where the electrical zones apply, which matters if the rooflight is going over a shower in a loft en suite.
Where the work is notifiable, an electrician registered with a competent person scheme can self-certify it and tell Building Control on your behalf, and you receive a compliance certificate afterwards. Where it is not notifiable, the electrician should still leave you a Minor Electrical Installation Works Certificate showing the spur was tested. Keep that with the rooflight paperwork, because a buyer's solicitor may ask for it later.
This is separate from the Building Control notification for the rooflight itself. Cutting a new opening in a roof, or replacing a rooflight, is building work in its own right, and we handle that notification where the work is notifiable. The electrician's certificate covers the circuit; our paperwork covers the roof.
How the electrician and the rooflight fit are coordinated
The electrician makes two short visits, set around the rooflight installation so no ceiling is opened twice.
- At the survey, we agree where the control unit will sit and where you will stand to use the switch. On a Romsey terrace with a side-return extension, that might mean a switch by the kitchen door and a control box above the ceiling near the rooflight kerb. This goes on the written light plan with the position, size and glass.
- First fix, before the ceiling is boarded, the electrician runs the mains cable to the spur position and we run the low-voltage cable up to the kerb.
- Rooflight fit, we install the unit, connect the actuator and sensor to the control box, and make the upstand weathertight.
- Second fix, the electrician connects the spur, tests the circuit and issues the certificate, and then we run the rooflight through a full open and close cycle from every control.
We arrange the electrician as part of the installation, so you deal with one firm and one programme. If you already have an electrician on site for an extension, we can work to their dates instead and give them the manufacturer's wiring details in advance. The practical detail of cable routes and spur positions is in our guide to wiring an electric rooflight.
In an existing room that is already plastered, the order changes a little. The cable has to be fished through the ceiling void or run in a neat surface route, and the electrician will want to check the circuit you are tapping into has RCD protection before any work starts.
When no electrician is needed
A solar-powered opening skylight avoids the mains question entirely, which is why it is often chosen for a rooflight added to a finished room.
A small panel on the frame charges a battery that drives the motor, the rain sensor and the remote. Nothing connects to the house, so there is no spur, no certificate and no chasing into plaster. The trade-off is winter performance on a north-facing slope, where short, dull days give the panel less to work with. Our guide to solar powered roof windows covers battery life and where they suit, and manual vs electric opening rooflights compares both with a simple winder pole.
A manually opened rooflight also needs no electrician. For a rooflight within reach, such as on a low single-storey extension, that can be the simplest answer, though a high skylight over a stairwell is easier to use for purge ventilation with a switch on the wall.
Questions people also ask
Can I use my own electrician?
Yes. Tell us at the survey, and we will share the control unit position, the power requirement and the manufacturer's wiring instructions so their first fix lines up with our installation dates.
Does a rain sensor need its own power supply?
No. On a mains system the rain sensor runs from the rooflight's control unit on low voltage, and on a solar unit it runs from the battery. There is one mains connection for the whole rooflight, not one per component. See rooflight rain and wind sensors for how they behave.
Can several electric rooflights share one spur?
Often, yes. Where two or three rooflights sit over the same room, one control unit or a shared supply can serve them, depending on the manufacturer's system. The electrician checks the load and the circuit, and we plan the control positions so every unit is operated from the same place.
Will an electric rooflight need an electrician again later?
Not for normal use. If you later add a smart home link or an electric blind, that is usually low-voltage or wireless work on the rooflight system. A move of the spur, or a new circuit, would bring the electrician back. For the full range of options, see our electric and opening rooflight installation service, or book a light survey.
