Question answered
How much do rooflights cost in the UK?
The short answer
A standard roof window typically costs about £350 to £600 to install in the UK, according to MyBuilder's guide updated on 21/08/2026, with the window itself listed at £305 and scaffold at around £500. Flat rooflights, large units and jobs needing structural work cost more, and those are priced on survey. Check what the total leaves out, VAT and scaffold especially.
The price on a window box and the price on your quote are different numbers. Fitting, scaffold, flashing and finishing sit between them and differ a good deal between roofs.
Unit price against installed price
When people ask what a rooflight costs, they are often comparing figures that measure different things. One is the price of the glazed unit from a supplier. The other is the price of having it cut into the roof, flashed, fitted and made good. MyBuilder's guide, updated on 21/08/2026, gives £305 for a standard centre-pivot roof window as a unit, and quotes installation as £350 to £600 for standard jobs, with labour and fitting inside that range.
These are typical UK numbers from one third-party guide, not prices from us. They suit a plain replacement, or a single new window in an easy spot. Anything beyond that moves the total: a bigger frame, special glass, an electric opener, a high or awkward slope. Ours follows a survey with photographs of the slope, and it is written as a single total.
Roof window or rooflight: the words matter
The trade uses two terms. Approved Document L defines a roof window as one fitted in the same orientation as the surrounding roof and in plane with it, while a rooflight is raised up on a kerb or upstand and sits clear of the slope. In everyday use, a roof window is the flush pitched-roof kind, and a rooflight is the raised kind you see on flat roofs.
The difference affects price and energy performance. Table 4.2 of Approved Document L gives 1.4 W/(m2.K) for roof windows, or a Band B rating as the other route, and 2.2 W/(m2.K) for rooflights. Flat roof rooflights also need an upstand, and the document limits one built on site to 0.35. The price guide we quote covers roof windows; rooflight costs lean more on the kerb and the roof around it, and are worked out after the survey.
What pushes the total up
Size comes first. A larger frame means more glass, a heavier unit and a bigger opening to form in the roof. The covering counts too: slate calls for more careful cutting and flashing than plain concrete tile. A new opening, where there was none before, means cutting rafters and fitting trimmers, which is structural work and costs more than swapping like for like.
Scaffold is a cost on any job above the first floor, and poles on the footway need a highway licence, which the scaffold firm applies for and which adds time. MyBuilder lists it at approximately £500 for roof window work, and gives £850 to £1,200 for a standard two-storey house in its scaffolding guide. Interior finishing is another question to ask: plastering the splay, lining the shaft and decorating. Check whether a quote includes VAT, which is 20% at the standard rate, and whether it includes scaffold, because those two items account for many of the surprises people meet later.
Flat roof rooflights and larger glazing
Flat rooflights, lanterns and walk-on glazing are made to size, with kerbs, upstands and often a bespoke finish. That is why one typical range does not do them justice. Lantern and pyramid styles, large sliding units and bespoke sizes sit well outside a standard window guide, and why they are priced on survey. The unit costs more than a standard roof window, and the roof around it must be dressed to suit, with the waterproofing carried up and over the kerb. Glazing type adds to the price: double or triple glazing, solar control coatings, self-cleaning finishes and opening versions each push the figure up, and walk-on glass is the dearest of all because of its thickness and strength.
If you are weighing the types, see the cost of a skylight or a roof window, and the guide to fitting a roof window in a flat roof. Where the plan is a loft room or a flat roof extension, glazing choices and thermal rules are closely linked, so decide the glazing before the insulation is specified rather than after.
Getting a quote you can compare
The more you send, the closer the first conversation gets to a firm figure. Send the make and model if you have it, the size, a photograph of the slope from inside and out, and the covering. Say whether this is a straight swap or a brand-new opening. The survey then covers access, the structure around the opening and the condition of the surrounding roof.
Expect the quote on paper, with one price at the bottom. Check that it names the product, the flashing kit, whether scaffold and VAT are in or out, and what the interior finish includes. Our page on whether roofers fit Velux windows explains who does which part of the work. For the whole service, see skylights and roof windows. Compare like with like, specification against specification, not headline numbers. A figure that omits the flashing kit or the scaffold only looks cheaper until those turn up as extras.
Rooflight pricing queries
Does the quoted price for a roof window include scaffolding?
Not always. MyBuilder lists scaffold at around £500, so ask whether it sits inside your total. A low roof sometimes needs just a tower; a window higher up the house usually calls for full scaffold.
Why is one rooflight quote so much higher than another?
Usually the product, the size or the work around it differs. A new opening needs structural trimming, a slate roof needs more flashing work and a flat roof needs a kerb. Ask each firm what is included, and compare totals only after the specification matches.
Tell us about your roof
Describe what is happening and we will call you back to arrange a visit.
- Photographs of what we find
- A written quote with one total price
- Or call 01903 299063
10-year workmanship guarantee, in writing.