Short answer: The VELUX window installation cost depends on the size code, how the window opens, the glazing, the flashing kit for your roof covering, any electric or solar operation, and the lining inside. Labour is lower when a window goes into an opening that already exists, and higher when a new opening means cutting and trimming a rafter. We give no figure without seeing the roof, and the price you are quoted is fixed and in writing after a survey.
Why a single VELUX figure would mislead you
Search for a VELUX fitting price and you will find numbers that run a long way apart, and none of them describes your roof. The window is a small part of the job. The same VELUX code can go into a slate terrace in Anfield, a tiled semi in Crosby or a bungalow near Formby, and the work around it is different each time: how the covering is lifted, how the opening is framed, how the lining is finished indoors.
So the useful answer is a list of what moves the price, in roughly the order it matters, so that you can see where your own job sits. We do not quote a figure here, and the page you are reading has none, because the cost turns on the roof itself, and only a survey shows it.
What sets the price of the window itself
Four choices belong to the window. The first is size. A larger code costs more to buy, is harder to handle on the roof and more often needs structural work; VELUX window sizes and codes explains how to read the code. The second is the way it opens. The two opening styles are priced differently, so settle which suits the room first; our page on pivot and top-hung opening compares them.
The third is the glazing. Glazing options are priced separately: standard double glazing, a laminated inner pane, a pane made to cut rain noise, or a higher-performance pane. Under Part L, a replacement roof window in an existing English dwelling has to reach 1.4 W/m²K, or Window Energy Rating band B instead, and the better panes clear that with room to spare. The fourth is how it operates. A manual window is the base. An electric one, from the INTEGRA range, adds a motor, a control and a rain sensor, and the solar version adds a panel and a battery in place of a mains supply. The electric version also needs power or control brought to the window.
| Choice | Simpler job | Bigger job |
|---|---|---|
| Size | Narrow CK or FK code | Wide PK, SK or UK code |
| Opening | Same type as the old window | Changing type, new clearances |
| Glazing | Standard double | Laminated or enhanced |
| Operation | Manual handle | INTEGRA electric or solar |
What sets the price of fitting it
The fitting depends on your roof. The flashing kit is the clearest example. Slate, plain tile and interlocking tile each need a different kit, and a combination kit for two windows stacked or side by side differs from a single one. Each kit is covered in our guide, roof window flashing for slate and tile.
Then comes the opening. Because the opening already exists, swapping like for like is quicker; replacing an old VELUX window walks through it. Where the roof has never had a window, we have to cut the covering, form the opening and trim it with new timber. Cutting a rafter means designing the structure around it, and on a trussed rafter roof an engineer's design comes before any timber is touched.
Access sits in the same group. How the work reaches the roof, and whether the window can be put in from the loft side, changes what has to be set up. Whether the work can be done from the loft side is answered in fitting a VELUX window from inside.
What sets the price of the finish indoors
Indoors, the lining is the final piece. When a swap keeps the existing lining, little extra is needed beyond sealing and trim. When the new frame sits differently, or a new opening is formed, a lining kit or a built plasterboard splay is needed, and then the decorating. Blinds and any fixed furniture around the window also have a bearing. A blind fitted to the new frame is a separate item.
There is a paperwork element as well. Under the Building Regulations 2010 in England, a new or replacement roof window counts as controlled work and Building Control must be told; we make that notification for you. It is part of the fixed quote, so it does not appear later as a surprise.
Several windows in one visit share the set-up and the clean-up, which is why we price a row differently from separate visits. A row of three on a long rear slope, flashed with one combination kit, is not the same task as three individual fittings. Comparing against a quote for another make? For that, the cost of fitting a roof window spans several makes, and our costs page shows how we price.
- The full size code from the old label, or a photo of it
- The roof covering: slate, plain tile or interlocking tile
- Whether the window must open, and how
- Whether any rafter needs cutting
- The lining you want to keep or change
How to get a price you can rely on
Begin by sending a photo of the label and one of the room, by WhatsApp or phone, and we will tell you whether it looks like a plain swap or something bigger. No price comes until we have surveyed the roof in person. You then get a written, fixed quote that names the window, the flashing kit, the lining work and the Building Control notification, and a ten-year written guarantee covers the labour. Get a free quote and you will see the cost of your own roof, itemised and based on a survey of that roof. For the wider picture of the range, the VELUX window installation page is the place to start.
Cost questions that come up after the quote
Is a quote for a swap cheaper than for a new opening?
Generally the swap involves less work, since the opening and its framing already exist. That said, an old opening that is damaged or non-standard can bring extra work of its own, which the survey reveals, so the answer is only certain once we have seen the roof.
Will an electric or solar window cost more than a manual one?
Yes, because the motor, the control and the rain sensor are extra, and solar adds its own panel.