The short answer
Fitting is the labour and materials around the glass: access to the roof, lifting the covering, setting the frame between the rafters, the flashing kit, the insulated lining and the plaster returns inside. A swap into an existing opening is the lightest version of that work, and a new opening in a slope with no window yet is the heaviest. The fixed written quote that follows our free survey names each part of the job.
- Free survey, fixed written quote
- 10-year workmanship guarantee
What the fitting side covers
The window arrives as a catalogue size. Everything done to put it into your roof is fitting, and it is made up of several pieces of work:
- getting safe access to the slope, from a ladder up to a scaffold, depending on the height of the house
- lifting the tiles or slates and setting the frame square in the opening
- weathering the edges with the flashing kit made for your type of covering
- building the lining that joins the frame to the ceiling and wall, insulated and boarded
- plastering the returns and leaving the surfaces ready for paint
Fitting also means what happens inside the house. Furniture and floors are sheeted, the ceiling is opened around the position so the rafters can be seen, and the opening is closed up and lined once the frame is weathered. A window that sits over a bed or a desk gets its sill position agreed with you standing in the room, because moving the glass a few hundred millimetres up or down the slope changes the lining and the trimming.
Taking the old unit away is part of a swap. Blinds and electric operation are ordered with the window and fitted on the same visit, and they are separate items on the quote.
A swap or a new opening
The biggest single factor is whether the roof already has a hole of the right size. Where it does, the old frame and flashing come off and the new ones go in. Where it does not, rafters may have to be cut and carried on a trimmer, and that is structural work that we design before we touch the slope.
The same logic applies to a pair of windows. Two units share one set-up and one clearing-away, but each has its own frame, kit and lining. That is why we price the pair from the roof rather than by multiplying.
| Job | Work beyond the fitting | Effect on the quote |
|---|---|---|
| Swap in the same opening | Strip old frame and flashing, check battens and lining | The lightest version |
| Bigger window in the same slope | Cut and trim rafters, new flashing kit, wider lining | Closer to a new opening |
| First window in a bare roof | Design the trimming, open the ceiling, new lining and plaster | The heaviest of the three |
| Window over a stairwell | Lined light well through the loft void | Adds a build inside the roof |
What the roof and the house add
Plain clay tiles, concrete interlocking tiles and slate each take a different flashing kit, and tiles that vary in thickness take more fitting care. A house with three floors beneath the roof ridge needs more access than a bungalow, so the height of the eaves feeds into the figure early. A loft that is full of stored boxes, or a ceiling that needs reboarding around the lining, adds time inside.
Position in the slope matters as well. A window set high needs a longer lining and a reach that calls for better access, while one near the eaves is shorter to build but sits closer to the gutter line and the roof edge. Where the rafters are irregular, as they can be in older Kent houses, we measure the actual gap before ordering and trim to suit.
Planning is rarely a cost on a house, because a roof window usually falls under Class C permitted development; our skylight planning permission guide sets out the conditions. The Building Control notification for the opening is on us where the work is notifiable.
Parts of a fitting quote
- AccessLadder, tower or scaffold, set by the eaves height and the slope.
- StructureRafters left alone, or cut and trimmed around the opening.
- Covering and flashingThe kit for your tiles or slate, and how much covering is lifted.
- InsideLining, insulation, plaster returns and any light well.
- ExtrasBlinds, an electric motor and its cable route.
Getting a figure for your roof
Send a photo of the slope from the garden and one of the room below, and book the survey. For what a window itself involves on the quote, read the guide to VELUX window cost, and the VELUX windows page covers the range we fit.
