Two rooflights that look alike from inside can cost quite different amounts to fit. The difference is almost always in the roof above them, the work needed to form the opening, and the glass and finish chosen. So we do not publish a price list. We survey the room, the spot and the roof, then give you a fixed written quote that does not change on the day. This page sets out what goes into that number.
The product
The rooflight itself
The unit is the part people picture first. Its cost depends on the type (a roof lantern, a flat rooflight, a roof window, a sun tunnel, a walk-on panel), its size and the glass inside it. Opening units, whether manual or electric, cost more than fixed ones. A conservation rooflight with a slim metal frame costs more than a standard roof window of the same size.
What moves the cost of the unit
- Type of rooflightLanterns and walk-on panels carry more glass and framing than a roof window.
- SizeBigger units use more glass and need stronger frames.
- GlazingTriple glazing, solar control and self-cleaning coatings each add to the unit.
- Opening or fixedManual and electric opening units cost more than fixed ones.
The roof
Forming the opening and weathering it
Most of the variation between jobs sits here. In a pitched roof, the rafters are cut and trimmed, the tiles or slates around the opening are taken up and relaid, and a flashing kit seals the frame to the roof. In a flat roof, the joists are trimmed, an insulated upstand is built and the roof covering is dressed up its sides. Replacing an existing rooflight in an opening that already works is usually less involved than forming a new one.
What moves the cost of the roof work
- New opening or replacementA new opening needs trimming, propping and making good.
- Roof coveringSlate, stone and some flat roof membranes take longer to work around.
- State of the roofBrittle slates or a tired flat roof may need work around the opening.
- AccessScaffold, roof ladders or lifting gear change the setting-up time.
Inside
The finish in the room
The opening leaves a reveal or light well inside, which is insulated, boarded and plastered so it matches the ceiling. A deep light well through a loft takes more lining than a shallow reveal in a sloping ceiling. Blinds, electric controls and any decoration are separate items you can choose to include.
Paperwork
Building Control and the guarantee
Where the work is notifiable, we handle the Building Control notification with the local authority or a registered building control approver, and the cost of that is in the quote. Every installation carries our 10-year workmanship guarantee in writing. Planning is separate: if your house needs a planning application, we tell you at the survey and explain the route, using our guide to planning rules in Derby.
Next step
Getting your own figure
The survey is free and there is no obligation. We look at the room, mark the spot you want lit, check the roof and then send a fixed written quote with each item set out. To arrange one, use the survey form on this page.
