In brief
The cost of installing an electric rooflight is set by six things: the size of the unit, the motor and controls, the glazing, the kerb it sits on, the electrical connection and how the room is finished inside. Two units that look alike can differ once those are added up, so the price comes as a written quote after a survey, not as a list.
- Unit size: a larger opening means more glass and a heavier frame, and calls for a bigger motor
- Motor and controls: wall switch, remote, rain sensor or a link to a home system
- Glazing: the pane build-up and any coatings you choose
- Kerb and structure: what the roof needs before the unit can sit on it
- Power: a mains supply, a solar panel or a battery-backed unit
Why a quote beats a price list
An electric rooflight is a glazed unit, a motor, some controls and a cable, set into a roof that has its own character. The maker's price covers the first three. The cable and the roof are particular to your house, which is why a single figure quoted without seeing either would be a guess.
Prices for fitted electric rooflights are set per job at the survey. The survey is free, and the quote that comes after it states the unit, the pane build-up, how long the maker will take to deliver and what your builder or electrician must provide. Our rooflight costs page sets out how each type of rooflight is priced, and the sections below deal with what is particular to the electric ones.
Size and the motor that drives it
Opening size is the first thing that moves the price. A bigger sash is more glass on a heavier frame, and it needs a motor that can lift it and hold it. Makers pair a given size with the right actuator, so you are not choosing the motor separately, but the larger the sash the more that part of the unit costs.
The way the unit opens also matters. Some tilt up at the top edge, some lift clear on a parallel arm, and some slide. Each has a different mechanism and a different range of sizes, and the choice should follow what you want from the opening: ventilation, an escape route or simply light.
If you are still deciding between a pole-operated unit and a motorised one, manual or electric rooflights compared sets out the differences in use as well as in outlay.
Controls and sensors
The simplest electric rooflight has a wall switch beside the door. From there the options widen: a handheld remote, a keypad, a timer, a link to a home automation hub, or a combination. Each adds to the cost of the controls and, for some, to the work of the electrician.
A rain sensor is the control most people ask about. It closes the sash when it detects wet, which matters for a rooflight left open while no one is at home. It is an extra on most units and has to be placed so that it reads rain accurately. We cover how the sensors work in the guide to rain sensors on opening rooflights.
Ask for the controls to be named in the quote rather than described as included. That way you can compare two quotes line by line.
Glazing and the finish of the unit
Glazing is the second big variable on the product side. Double or triple panes, solar control coatings, self-cleaning finishes and laminated glass each carry a cost, and the weight they add can affect the motor. The frame can come in a choice of colours and materials, which also has a cost.
Thermal performance is part of the choice. For existing homes, Part L of the Building Regulations asks a roof window to reach the window energy rating of Band B, or 1.4 W/m²K, and sets 2.2 W/m²K as the figure for a rooflight. The unit we name in the quote will be one that meets the figure for its type, and the glazing you choose can take it further.
The kerb, the roof and the electrical connection
On a flat roof an electric rooflight sits on a kerb, a raised upstand whose top edge is with its top edge commonly 150mm or more clear of the finished roof, as the maker instructs. If the roof is being built, the kerb goes in with it and the cost is small. If the roof is finished, the covering has to be opened and made good, and a roofer may be needed.
The connection is the part that is bought separately. A mains-powered unit needs a cable run from a fused supply to the motor and to the switch, and that is done by a qualified electrician. Some units are low-voltage with a transformer, and others run on a solar panel with a battery, which removes the cable run but not the cost of the panel. Our answer on whether an electrician is needed and the guide to wiring an electric rooflight set out what has to be in place.
Cable routes also change the price. A short run in a loft with open joists is simple. A long run through a finished ceiling means chasing, making good and redecorating.
Getting a quote that holds together
Book a free survey and the roof, the exact position of the opening and the route for the power are all checked. Your quote then lists the unit and its glazing, the controls, the maker's delivery time, and the items the builder has to supply, such as the kerb size in writing ahead of the roof deck.
If the roof is not built yet we can price from drawings and confirm on site later. Tell us what trades are already booked: if the electrician is on site for first fix anyway, the cable run costs less, and the plasterer can finish the reveals once the unit is in. For the wider range of what we install, see our electric opening rooflights page.
Related questions
- Is an electric rooflight dearer to run than a manual one?
- The motor only works while the sash is moving, so it is not a running cost to worry about. The difference is in what is bought and installed: the motor, the controls and the electrical connection.
