How much does an electric rooflight cost?
An electric rooflight costs what the equivalent fixed rooflight costs, plus four separate items: the actuator and its control unit, the electrical supply that feeds it, the controls you choose, and a small amount of extra time on site to run the cable and set the limits. Those four move independently, which is why two motorised units of the same size can sit a long way apart.
Sunspire quotes in two stages: a range by email once the basics are known, then a fixed written figure after a survey. This page sets out what moves the number between those two points so that competing quotations can be read against each other. The installation itself is covered on electric rooflight installation, and whether the uplift is worth paying is a separate question answered on whether electric rooflights are worth the extra cost.
The drive, and why its rating is the biggest variable
Actuators are not one component at one price. A slim chain drive rated for a light double glazed sash and a self-locking spindle drive rated for a heavy triple glazed pane are different pieces of engineering with different casings, motors and gearboxes.
The rating is set by what the sash weighs and how far it has to travel, not by the size of the opening. This is why glazing decisions feed straight into the drive cost. Specifying laminated outer panes for rain noise, or triple glazing on an exposed plane, adds mass that the actuator has to lift against gravity on every cycle for twenty years, and the drive is sized accordingly.
Getting mains to the transformer
The electrical item varies more than anything else on the job, and it has nothing to do with the rooflight.
Taking a fused spur off an existing circuit in the same room, where the wall is open or the route is short, is a small piece of work. Running a new circuit from the consumer unit across a house, through finished rooms, lifting floorboards upstairs and making good afterwards, is a different order of item entirely. On a new extension where the electrician is on site anyway and the ceiling is open, the marginal cost is close to nothing.
Cable route, and the moment it stops being cheap
The low voltage run from the control unit to the head of the rooflight is a few metres of thin cable. Its cost is almost entirely labour and making good.
At first fix, with joists exposed, it is minutes. Through a finished plasterboard ceiling it means lifting boards, or chasing, or accepting surface trunking across a ceiling that was meant to be plain. On a warm deck flat roof, where the insulation sits above the deck and there is no void below it, there may be no concealed route at all once the build-up is complete. That is the point at which a solar unit stops being second best and becomes the sensible answer.
Controls, from a wall plate to a gateway
Control cost climbs in recognisable steps. A single hard-wired wall plate is the base. A radio handset with a receiver in the control unit is a modest step up. Wireless wall plates add a little again, and are usually worth it because a switch that stays where it was put gets used.
Above that sit the sensors and the network gateway. A rain sensor is a small item on its own but it is often bundled into a package rather than sold separately. A gateway that puts the unit on the home network and into an app adds a box, a network connection and a commissioning visit. Whether that earns its place is set out on opening a rooflight from your phone.
Doing the blind in the same visit
An integrated blind runs in side channels within the frame, and a motorised one takes a tubular motor in its head. On most systems it draws power from the same control unit as the opener.
That is why the two are far cheaper together than apart. One control unit, one supply, one commissioning, one visit. The second low voltage cable at first fix is a few metres of wire. Ordering the opener now and the blind in two years means a second power source or a battery version, and a second lot of setting up. The timing question is covered on adding electric blinds later.
The building work, which is unchanged by the motor
Everything that drives the cost of any rooflight still drives this one. Size, because past roughly a metre and a half in either direction the structure changes and the glass becomes a special order rather than a stock item.
Access, because a rear extension roof reached from a garden is straightforward and a third floor slope over a narrow side return is a scaffold with a hire period attached. Structure, because a steel brings a calculation and a longer programme. And the covering, since re-laying hand-made clay tiles around an opening in Thaxted or Coggeshall is slower and more skilled than dressing a single ply membrane on a Harlow flat roof.
Comparing what a motor adds, item by item
| Item | What drives it | Cheapest moment |
|---|---|---|
| Actuator and control unit | Sash weight, stroke, drive type | At order, with the unit |
| Mains supply | Spur off an existing circuit, or a new one | While the electrician is on site |
| Low voltage cable | Whether the route is open or closed | First fix |
| Controls and sensors | Wired plate, handset, sensor, gateway | At order |
| Commissioning | Number of units and controls to pair | Installation day |
Reading a quotation for a motorised unit
A quotation worth comparing names the manufacturer, the model, the external frame size, the glazing specification with its U-value and the frame finish, exactly as a fixed unit would. Then it names four more things.
The actuator type and its stroke in millimetres. The power arrangement, and whether the mains side is included or expected from someone else. Which controls and sensors are in the figure. And who is commissioning the unit and setting the limits. It should also confirm that the Building Control notification for the rooflight is included, which Sunspire handles as part of the job.
What is needed for a sensible range by email
Less than people expect. A photograph of the roof from outside, one of the ceiling from inside, a rough room size, and the approximate height from the floor to where the glass will sit.
Then two more answers that are specific to a motor. Is there an existing circuit in that room, and is the ceiling still open or already finished. Those two decide whether the electrical item is small or substantial, and they are the difference between a useful range and a guess. Broader cost thinking across job types sits on the costs page.
Related questions
Tell us about your roof
We start with the building, the covering and the slope. Then we tell you what will suit it, and what it will cost, as a fixed written number.
- Surveyed before it is priced
- 10-year workmanship guarantee
- Building Control notification handled
- New installations and replacements