How much does an electric rooflight cost?

The motorised unit itself is the predictable part

A manufacturer sells the same rooflight in a manual version and a powered version, in the same sizes, with the same glass options and the same flashing kits. The powered version carries a chain or spindle mechanism concealed in the head of the sash, the wiring loom that serves it, and usually a rain sensor as standard. That difference has a published price attached to it and it does not change once the survey is done.

What can change the supply figure is the glass you choose at the same time. A solar control coating or a triple glazed sash costs more to buy and nothing extra to fit, so if a room faces south and the vent is going in for heat as much as for air, the sensible moment to spend is at the order.

Getting a cable to the head of the frame

This is the line that moves. A powered unit needs a low-voltage supply arriving at the top of the frame, fed from a control unit that itself sits on a fused connection somewhere sensible in the house. The question is what stands between that control unit and the rooflight.

In a new opening, in a roof that is coming apart anyway, or in a loft conversion where the plasterboard has not gone up, the answer is almost nothing. The cable is dropped in while the structure is open and the cost is a few metres of cable and half an hour. Our page on wiring an electric rooflight at first fix covers the sequencing.

In a finished, plastered, decorated room the answer is very different. Boards come up, plaster is chased, a route is found down a wall, and everything that was disturbed has to be made good and redecorated. That work is often larger than the price difference between the manual and the electric unit.

The electrician’s element, and what it covers

We install rooflights. The electrical work is carried out by a qualified electrician, engaged either by you or coordinated by us, and it is a separate line in the overall spend rather than something buried in ours. It covers providing the supply, fitting the isolator, terminating at the control unit, and certifying the installation.

The size of that element depends almost entirely on whether the electrician can work alongside other trades on an open structure or has to come back to a finished house for a single connection. A minimum charge for one visit to connect one unit is poor value. The same electrician connecting three rooflights, two wall switches and a run of lighting on the same afternoon is not.

Solar units trade cable cost for unit cost

A solar-powered rooflight puts a small photovoltaic panel in the top of the outer frame and runs the mechanism from a battery it charges itself. It costs more to buy than the mains version of the same window and nothing at all to supply, because there is no cable, no control unit on a fused spur and no electrician.

In an existing plastered ceiling that arithmetic usually favours solar by a wide margin, and it removes the disruption as well as the cost. On a north-facing or heavily shaded slope it is a weaker choice, and we would say so at survey rather than after. There is more on this on whether solar powered rooflights are any good.

Controls, sensors and the things people forget to price

The mechanism is one purchase. What you operate it with is another, and it is easy to leave out of a comparison.

• A hard-wired wall switch costs little in parts and needs the cable decided during the electrical work.
• A handheld remote usually comes in the box on wireless systems.
• A battery wall keypad is an extra item, and it is the standard control for a solar unit.
• A gateway for home network control is a separate purchase again, and one gateway serves several units.
• An internal electric blind is a further unit cost, and it is far cheaper ordered with the rooflight than added later.

Blinds are the one to think about hardest. The factory builds the brackets into the frame, so a blind ordered at the same time drops into fixings that already exist.

Access is still the biggest single line

None of the above changes the fact that the largest number in most rooflight quotations is getting people and materials safely onto the roof. A single storey rear extension reachable from a tower is one job. A rear slope on a three storey terrace with no side access is another, and the scaffold is priced by the scaffolder rather than by us.

Electric operation does not add to that figure. It does mean the electrician’s visit has to be timed against the same programme, which is a scheduling matter rather than a cost one, provided somebody has thought about it in advance.

Several units on one visit is where the premium shrinks

The fixed costs of an electric installation spread well. One control unit can serve a group of rooflights, one wall switch can drive a bank of them, one electrician’s visit can commission the lot, and one cable route often carries the whole run. The second and third powered units on a job carry a much smaller premium than the first.

The reverse is also true. A single electric rooflight added to a finished room, on its own, with a dedicated cable run and a dedicated electrician’s visit, is the most expensive way to buy one.

How we put a number on it

Send photographs of the roof and the room, tell us whether the ceiling is open or finished, and we will send a realistic bracket by email. It will be wide, because an honest bracket has to be. The fixed price follows a survey, where the cable route, the access arrangement and the covering are all established rather than assumed.

We install new rooflights and full replacements across Oxford and up to twenty five miles by road, with fifteen years in the trade, VELUX, Fakro, Keylite and Roto units, and a ten-year workmanship guarantee. Call 01865 704245 or email info@heritageskylightsoxford.co.uk.