Do electric rooflights need a socket in the roof?

What is actually needed

Most systems run the actuator at extra low voltage from a transformer or control unit. So the mains connection is to that unit, and what runs to the window is a low voltage cable.

The transformer usually sits in the loft or a cupboard, somewhere accessible but out of sight.

Some systems are mains at the window instead, in which case the connection is made in a suitable enclosure at the unit.

Run it at first fix

Before plasterboard, a cable to the rooflight position is a few metres clipped to a joist. Twenty minutes.

Afterwards it means lifting flooring or ceiling, chasing for a switch drop, and making good. A day and a half plus decoration.

Run a capped cable even if you fit a manual unit. It costs almost nothing and it keeps the cheap option open.

The switch

Fit a wall switch as well as a remote. The remote is always in another room. Position it with the light switches at the room entrance.

Bathrooms

Zoning rules apply and the specification follows from which zone the unit is in. An electrician’s decision, and it belongs in the specification from the start.

The alternative

A solar powered opener needs no supply at all. Panel on the sash, battery in the frame. On a finished room that is usually the right answer.

No, and nothing sits outside

There is no socket, no external connection and nothing on the roof that carries mains voltage. The whole electrical arrangement sits inside, on the warm dry side of the window.

A typical mains system has three parts. A fused spur from a convenient circuit to a control unit, usually located in the loft or a cupboard. A low voltage cable from that control unit to the actuator on the window frame. And, where fitted, a cable to a wall switch.

The run from the control unit to the window is generally extra low voltage, which is why the cable is modest and why the arrangement is safe in a position that gets condensation.

Where the control unit goes

Somewhere accessible: a loft, an airing cupboard, a service void. Not buried behind plasterboard.

It is the part most likely to need attention over twenty five years, and burying it turns a ten minute job into a disruptive one. We agree the position before the wiring is run rather than putting it wherever is convenient on the day.

What the electrician does

The spur and the connection to the household supply, and the certification. That is electrical work and it needs a competent electrician; depending on where the work is it may also be notifiable under Part P.

The low voltage side and the actuator connection are part of the rooflight installation.

The alternative that needs none of it

A solar powered opener carries its own photovoltaic panel and rechargeable battery on the unit itself. No spur, no control unit, no cable, no electrician, and no making good.

For a retrofit into a finished room it is usually the sensible answer, and it costs far less overall than running mains through a completed ceiling.

Weather and the panel

On a solar unit the panel is the only part outside, and it is integrated into the frame or the flashing rather than being a separate item. It is sealed, it is designed for the position, and it needs no maintenance beyond staying reasonably clean.

The advice for anyone building

Run a capped cable to every rooflight position at first fix, even if you fit manual or solar units. A few metres clipped to a joist before the plasterboard goes on costs almost nothing, and it covers a future motor, a future blind and a future rain sensor.

Terminate it in an accessible enclosure and photograph where it is before the ceiling closes.

Where the control unit should go

Somewhere you can reach: a loft, an airing cupboard, a service void. Not buried behind plasterboard.

It is the part most likely to need attention over twenty five years, and burying it turns a ten minute job into a disruptive one.

We agree the position before the wiring is run rather than putting it wherever is convenient on the day, and it goes on the record with the rest of the specification so nobody has to hunt for it in fifteen years.

Where the room is already finished and a cable route would mean lifting floors or chasing walls, a solar powered opener needs no control unit and no cable at all, and it is usually the sensible answer.

No, and that is not how it is wired

A powered rooflight is wired as a fixed connection rather than plugged into a socket. A cable runs from a fused spur or a control unit to the actuator, terminating at a designed entry point in the frame.

There is no socket in the roof void, no plug, and no exposed connection at the unit.

What is actually involved

A supply taken from a suitable circuit, a means of isolation, the control unit or switch position, and the cable run to the rooflight.

It is notifiable electrical work and needs certifying by a competent person, and that certificate is part of the paperwork you should end up with.

Why timing matters so much here

Running the cable while the roof is open and the ceiling is off is straightforward and costs very little.

Running it afterwards means either surface trunking, which is visible, or opening up a finished ceiling and reveal, which means replastering and redecorating.

That is why the powered decision should be made before installation. Even if you fit a manual unit, running the cable at the time keeps the conversion available for almost nothing.

The alternative that needs no wiring

Solar operation. A small panel on the outside of the unit charges a battery and a remote operates it. No cable at all, which on a retrofit into a finished room is frequently the deciding factor.

The trade is a battery with a service life of a few years and slower operation. On a unit that gets used occasionally rather than daily, that is a good bargain.

Controls

Plan the grouping before the cable runs. Rearranging which switch operates which unit afterwards means going back into the ceiling.