Velux fitting cost
How much does it cost to have a Velux window installed?
MyJobQuote puts a standard mid-range Velux window at an average of £1,100. What your own roof adds or saves is settled at the survey.
The short answer
MyJobQuote reports £1,100 on average for a typical mid-range Velux. Separately, a Checkatrade table lists rooflight replacement (a Velux, for example) from £1,000. Neither number comes from us. A brand-new opening in the slope costs more than a swap into an existing one, and the roof, the size and the finish all move the total. We give one written total price after a survey.
4 min read · Part of Roof windows & skylights
The published figures
Two sources give a starting point. MyJobQuote's page on Velux windows and skylights, last updated in September 2026, reports an average of £1,100 for a typical mid-range Velux, and states no VAT basis. Checkatrade's rate table, which says its costs exclude VAT and access equipment, lists rooflight replacement (a Velux, for example) from £1,000. That is a from figure, so treat it as a floor for the table, never as a typical bill.
MyJobQuote adds that a Velux window replacement costs around £100 less for a straightforward swap, as the opening is already in place. A first window in a slope that has none is more work, and neither figure is a quote for it.
Neither source is a price from us, and neither says how big the window or how awkward the roof was. A national average knows nothing about your roof, your access or the finish you want inside the room, which is why the figures are best used as a sense-check on a quote, and not as a way to predict one. If a price comes in far below both, ask what has been left out.
What moves the price
Two roof windows of the same size can cost very different amounts to fit, because the work around the glass differs from roof to roof, and because no two openings start from the same condition. The table shows what pushes a job each way, and why.
| Factor | Why it matters |
|---|---|
| New opening or swap | A new opening means cutting rafters and trimming the structure |
| Size and type | Bigger, opening or electric windows cost more |
| Roof covering | Slate, tile and flat finishes need different flashings |
| Access | Height and a pavement frontage can call for scaffold |
| Inside finish | Lining, plaster and decoration after the fit |
A quote that leaves any of these out can grow once work starts, so ask what it covers. Cost also follows the room: a window over a stairwell needs different access from one over a bedroom, and a long reach from the ladder to the opening can add time. Blinds, trickle vents and extra flashing kits for grouped windows are further add-ons worth asking about.
Rules that shape the job
A new roof window must meet Part L. Until 24 March 2027, AD L 2021 Table 4.2 holds roof windows to 1.4 W/m²K, or to WER Band B on the energy label, and leaves the 2.2 limit to rooflights. Always ask for the rating before you order. A window that meets it is a sound buy, and a cheaper one that does not is no saving.
Planning is a separate question. A window in the slope of a house is normally covered by Class C of permitted development, subject to its limits on projection from the roof plane, while flats, listed homes and some designated land have their own rules. Our planning permission guide sets them out in full.
Dover District Council lists installing roof lights among the work it wants approved, so on an address in that district we confirm the route with the council first. Everywhere else, we ask the local building control team before ordering the window. Both calls are made before you commit, and nothing is ordered until the route is clear. Waiting for an answer can set the start date.
Comparing quotes fairly
Quotes are comparable only when each covers the same job. Before accepting one, check that it names:
- the make, size and type of window
- whether it is a new opening or a swap
- whether VAT is included
- whether scaffold, where the job needs it, is included
- what the finish inside the room covers
- who clears away the old window and the waste
We survey the roof and the room, then hand you a single written price, scaffold included where needed, so there is nothing to add on the day, and no surprise when the work begins. We would sooner you compare like with like than pick the lowest number on the page. Keep every written price you are given, so you can set them side by side later, and note the date each was given. If a swap is all you want, our page on replacing an old Velux like for like explains what that involves, and the roof windows and skylights page covers the wider service.
If you are still choosing a make, our comparison of Velux, Keylite and Fakro helps with that part of the decision. Settle the make and the size first, because every other part of a quote depends on them.
More questions
Is a Velux window cheaper to fit than another make?
The published cost figures cover Velux windows in general, not make by make, so a price for yours follows the survey. Size, type, finish and the roof matter more than the badge on the frame. Once the survey is done we can give you a total for any make you prefer, and say whether the choice changes the flashing or the lining needed.
Does the quote include scaffold?
Where the job needs scaffold, it sits inside the one written total, so there is no extra figure to add on top. Where the work can be done from inside the loft, none is needed. Whoever quotes you, ask them to confirm in writing what is covered.
Tell us what's wrong with the roof.
You'll get one written total price.