A roof window is bought in two halves: the unit itself, and the work of getting it into a pitched roof without letting water in. The two are different jobs, and a quote that blurs them is hard to compare. This guide pulls them apart. It sets out published national ranges for the window, the fitting and the scaffold, names the source and date of each, and then looks at the factors that belong to roofs around Stroud: slate and stone coverings, lead flashings, conservation-grade products and steep hillside access.
Every number here is a published guide price, not ours. They were gathered by outside cost guides and serve as a yardstick. Our own number follows a survey, in writing. How long the work takes is a different question, answered in how long it takes to fit a roof window, and the wider service sits on our roof windows and skylights page.
What the window itself costs: centre-pivot against electric
MyBuilder's roof window cost guide, updated in August 2026, puts a standard centre-pivot roof window at £305. An electric one is listed at £420 to £590. Those are the prices of the unit alone, before anyone has cut a hole in a roof.
The difference is in how the sash moves. A centre-pivot window turns on a hinge set about halfway up the sash, so the lower edge swings out and the upper edge swings in. You push it open by hand from a handle along the top. An electric window opens and closes with a motor, which earns its extra money where the window sits out of reach, over a stairwell for example, or where you want to shut it from a switch when rain starts.
| Item | Typical national figure | Source |
|---|---|---|
| Standard centre-pivot window | £305 | MyBuilder, August 2026 |
| Electric roof window | £420 to £590 | MyBuilder, August 2026 |
| Fitting, standard job | £350 to £600 | MyBuilder, August 2026 |
| Scaffold for the work | about £500 | MyBuilder, August 2026 |
What else moves the unit price
Size is the obvious one, because a wider and taller sash needs more glass and a bigger frame. The glazing specification matters too. A roof window going into an existing home has to meet Approved Document L: a U-value of 1.4 or better, or Band B on the energy rating label, however much you spend. Finish also counts: a plain white lining and a wood finish are not the same product. Our tour of skylight types explains which kinds of unit suit which roofs before you start comparing prices.
What the £350 to £600 fitting figure buys
The same MyBuilder guide gives £350 to £600 for installation on standard jobs, covering labour and fitting. Read that wording carefully. It describes a straightforward replacement or a simple new opening, and it does not promise to include every extra the roof throws up.
On a new opening the work runs in a fixed order. First the slates or tiles come off around the marked position, the rafters are exposed, and the opening is framed so the load of any cut rafter is carried round it. The window goes in, the flashing kit is dressed over the covering, and the lining is finished inside. Each step takes time, and each can grow. A roof window swapped into an opening that already exists skips the carpentry, which is why a like-for-like replacement tends to sit at the lower end of a range and a fresh opening in a rafter-framed slope sits higher.
When two quotes for a roof window differ by a few hundred pounds, ask first what each includes: the flashing kit, the internal lining, plastering, decoration and the removal of waste. The cheaper quote often leaves some of those out.
Extras that fall outside a standard job
Plastering and decorating the reveal inside are normally a separate trade. A rotten rafter found when the covering comes off needs repair before anything is fitted. A window in a room that is being converted may need wiring for the electric opener. Where the structure around the opening has to be strengthened, the figure waits for the survey, so it is added to our quote only if needed. Our guide to Building Regulations for roof windows covers the paperwork that comes with cut rafters.
Scaffold: the cost that surprises people
MyBuilder puts scaffold for a roof window job at about £500. Set that beside a whole-roof job: MyBuilder gives about £1,125 for a re-roof scaffold, while Checkatrade (October 2026) gives £700 to £1,300. A window is a small job, but the scaffold is sized by the height and width of the building, not by the size of the hole, so the cost can look out of proportion to the window.
A window in a rear slope of a bungalow can often be reached with a tower. A window on the high side of a three-storey house, or in a roof above a drop, needs a working platform along the whole eaves for safe access. Stroud adds its own wrinkles. Many houses here sit on terraced hillsides, with lanes too steep or narrow for a lorry to pull alongside, and a scaffold that has to be stepped to follow the ground costs more to design and put up than one on a flat plot. At the survey we study how the scaffold will reach the slope, and the quote carries that cost from the start.
Sharing a scaffold
If a roof window is only one of the jobs the roof needs, do the work together. A scaffold that is already up for re-slating, a ridge repair or new lead can serve the window at little extra cost, whereas a separate visit later pays for the same boards twice. The sensible time to fit a window into an old slate roof is often while the roof is stripped, since the slates around the opening can be laid properly and not cut in to an old covering.
Slate and stone: why flashings change the bill in Stroud
A roof window arrives with a flashing kit, the set of formed metal pieces that carry water round the frame and over the covering. The kit is made for a range of tile and slate profiles, but it is only half the weatherproofing. How the covering is laid up to it decides whether it keeps water out, and that is where roofs round Stroud differ from a plain concrete-tiled estate.
Natural slate and lead
Around a window set in natural slate, the slates are cut and fitted tightly to the frame, and lead is often used for the stepped sides. Checkatrade's repair guide gives stepped lead flashing at £80 to £120 per metre in Code 5, excluding VAT, and Leadworx calls Code 4 the usual pick for general flashing. A window needs a run of flashing down each side, so the metre count adds up quickly. A slater's day rate in MyBuilder's slate guide is £200 to £300, which gives a feel for the labour behind each cut slate.
Cotswold stone slate
Stone slate is a different job. Cotswold District Council's 2000 guidance describes roofs laid in diminishing courses, with the longest slates along the eaves, the shortest by the ridge, and random widths between. A kit designed for a regular tile cannot simply be dropped onto that. The courses around the opening have to be set out so the laps stay sound, and the stone itself is heavy, about 1,000 kg for every 10 m² according to the same guidance. Checkatrade's slate guide puts stone slate re-roofing generally at about £160 to £210 per m², a national figure rather than a Cotswold one. For a window in stone we price after the survey, since the count of slates to be re-laid around the frame only shows once the slope has been inspected.
Conservation rooflights and older houses
A conservation rooflight sits flush with the slope, with a slim metal frame and a single pane that lies close to the covering. It is made for older roofs where a standard window, with its thick frame standing proud, would look wrong from the lane. The national guides we use do not publish a price for these, so a conservation rooflight is priced on survey. Maker, size and frame finish all move the figure.
Rules shape the choice more than money does. A roof window is permitted development under Class C only if it stays within 0.15 m of the plane of the original roof, and a flush rooflight is designed with that in mind. Our guide to roof windows and planning sets out the full Class C test. Conservation areas and the Cotswolds National Landscape do not remove that right, but an Article 4 direction can, and a listed building needs consent for anything that affects its character. Stroud District has 41 conservation areas, so raise it with Stroud District Council's planning team before ordering.
Listed buildings add a step
If the house is listed, the written consent comes before the window, and the application may need drawings. That is time and sometimes a fee, which belongs in the budget for the job but is not part of the roofer's quote. We talk through the consent route at the survey, and we deal with the Building Regulations notification where the work calls for one.
Reading a quote
After the survey, the written quote we send covers the whole job. For a roof window that normally means: scaffold; the window; the flashing kit; the opening, including framing; the work in the covering around it; the internal lining and making good; and the removal of waste. The quote shows VAT too. The government's VAT Notice 708 treats roofing work as normally standard-rated, at 20 per cent, so a price quoted without VAT will rise when the tax is added.
The survey also gives us photographs of your own roof, which let you see what we saw and make sense of any line that depends on the condition of the slope. The work then carries a 10-year workmanship guarantee, set out in writing.
Comparing like with like
When you hold two or more quotes side by side, check that they name the same size of window, the same opening method and the same scaffold. A cheaper figure that quotes a smaller pane, leaves out lead, or omits the lining is not the same job. On a stone or slate roof, look for a line confirming the covering around the window will match the original material.
For a figure on your own roof, send the window size if you know it, plus a few photographs of the slope, through the enquiry form or on WhatsApp. You can also ring 01453 933613 to book the survey.