How Much Does it Cost to Install a Roof Window?

Roof windows come in different sizes and types, from domes and tunnels to non-opening and opening windows.

Velux is a well-known brand in the UK, so well known that their name has become synonymous with all roof windows. They are, in fact, just one of several firms that manufacturer roof windows.

If you want to know how much it costs to replace a roof window, then you’ve come to the right place. Our price guides are one of the most popular features on our site.

We can also help you source a competitive quote for replacing roof windows on your property.

We last updated our roof window prices on the .

Roof window in bathroom

Photo shows a Velux roof window with a centre pivot

For the avoidance of any doubt, this page refers to Velux (opening) roof windows that are installed on a pitched and tiled roof.

We also assume you already have a roof window and just want it replaced with one of the same size. Replacing windows like this is fairly straightforward as most can be replaced like-for-like.

If you want the new roof window to be larger than the original (a common request) or you want one installed for the first time, this will cost more because new timbers, plasterboard and plastering will be needed.

What Type of Business Installs Roof Windows?

Almost all roofing firms install roof windows, as do many double glazing installers.

We’ve come across a few double glazing firms that don’t install roof windows but most do.

Typical Cost to Install Roof Window

We know how much it costs to replace a roof window because in 2015 and again in 2018 we sent out price requests to dozens of roofers and double glazing firms.

The prices below are based entirely on the figures we were given.

You can use this a realistic guide to roof window installation prices.

Don’t forget; you can get your own quote here.

Example 1 – Small Roof Window 66cm x 98cm

The price below is to remove a small roof window and replace it with one of the same size – 66cm x 98cm.

The new window will be manufactured by Velux, made from pine, with laminated glass and is centre-pivoted. The window is manually opened, not electric.

The figure includes a new roof flashing kit, collar and insulation. All waste material including the old window will be disposed of by the contractor.

The cost of access equipment is included in the figures.

LocationSmall Business /TraderLarger Business (5+ employees)
London Area£900.00£1050.00
South, SW and Midlands£775.00£975.00
Outer Region and North£750.00£875.00
Need a Custom Price? >Compare Up To 3 Personlised Quotes Here

Example 2 – Large Roof Window Cost 134cm x 160cm

Thr second price we requested was for a larger window, this one is 134cm x 160cm, the frame will also be made from pine, with laminated glass and centre-pivoted.

The contractors have again included the cost of access equipment and waste disposal.

LocationSmall Business /TraderLarger Business (5+ employees)
London Area£1300.00£1350.00
South, SW and Midlands£1275.00£1375.00
Outer Region and North£1200.00£1200.00
Need a Custom Price? >Compare Up To 3 Personlised Quotes Here

What’s Excluded From These Prices?

Not included in our cost examples above are the following extras which you may want or need when replacing a roof window:

  • Scaffolding equipment, most roof window installers will have their own access equipment for their workers to get on the roof. If the roof is unusually difficult to access, then a scaffold may need to be hired in. Scaffold costs are explained here but aren’t included in our roof window price guide.
  • Security glass – strong reinforced glass is available for consumers concerned about security
  • Electric powered openers can be fitted, these cost extra
  • Opening rods can be installed, these allow you to open the window even it’s located very high up
  • You can even install a Velux window that has a rain sensor, this activates a motor which will close the window automatically.

What Are Flashing Kits?

A flashing kit is sold separately and is fitted around the window to prevent rainwater from entering the property.

Roof window flashing kits

Our price guide includes a new roof flashing kit.

We suggest you ensure any new window comes complete with a new flashing kit as older ones are prone to leaking and shouldn’t be re-used.

Ventilation Options

Many modern homes are so airtight and well insulated that some form of “trickle” ventilation is needed to prevent mould and condensation.

This is especially bathroom windows where moisture can build up.

Velux and many other window manufacturers now produce roof windows with variable ventilation settings:

  1. Locked – the window is fully closed and locked with no ventilation
  2. The window bar is open and the room is vented but the window is still locked and secure, it cannot be opened from the outside
  3. Open – The window is fully open and vented but not secured

Older roof windows do not have this feature but almost all modern variants do.Saving Money

How to Save Money

You might be able to save money  by:

  • Choose a cheaper alternative. Velux is a well-known brand but they are also the most expensive. Cheaper competitors offer very similar products at lower prices.
  • You might be able to repair any existing roof windows you have. Misting and condensation can usually be fixed by replacing the panes of glass or seals. Water leaks from the roof can often be fixed by inspecting tiles around the window(they often slip) or by replacing the flashing kit with a new one.

Do Roofers Have a Trustworthy Reputation in the UK?

Trustworthy Tradespeople UKHow trustworthy are roofers compared to the other trades in the UK.

We asked over eight thousand people this question.

See where roofers rank compared to other trades such as plumbers and electricians.

Explore the results and cast your own vote.


Get a Quote Today

Studies have shown that you can save up to 24% by getting 3 or more quotes for roof repair and maintenance work.

That is just one of many reasons why we have partnered with Rated People, the United Kingdom’s most trusted consumer quotation service.

They can supply you with up to 3 written quotes for a brand new roof window.


Rated People Have Appeared in:

Quote from Rated PeopleWhy We Love Rated People:

  • Only Real Customers Can Leave Reviews (unlike other sites where anyone can)
  • Over 1 million Jobs Posted – By Customers Just Like You
  • Avoid Time Wasters – These Are Genuine Roofers Seeking Work
  • Trusted Service – Rated People Has Been Around for Ten Years
Click Here to Get Your Free Roofing Quote

Not ready to get quotes? See all of our cost guides here

7 Responses to “How Much Does it Cost to Install a Roof Window?”

  1. Patrick BeerSeptember 12, 2015 at 10:27 am #

    There’s some pretty sound advice here which I found very useful. I’ve been quoted £6000 for replacing four roof windows and thought this was pretty extortionate. After reading this I will do some more reasearch!

  2. Ali rajaOctober 8, 2015 at 7:37 am #

    There’s good advice here which I found very useful. Very strong and easier to use than I imagined it would be. Would recommend this product to other people,can you sow me related with it some post, tn i will use this service very well.

  3. Ed SpencerNovember 4, 2015 at 1:28 pm #

    Hi, don’t want to burst anybody’s bubble but I have had quotes from rated people’s paying customers and they have been extortionate…one guy that I actually employed (to do some manual groundwork around my house) told me that the job would take one to two days to complete and hence the hefty labour cost so I agreed his price. He turned up two days later at about 9.30 and was done and dusted and gone by 1.30 not including the hour and a half when he disappeared to get lunch and pick up a replacement flag for the one he had broken….less than two and a half hours of work! I didn’t understand that ground workers were charging out at junior lawyers rates. I have requested quotes from rated people on a number of occasions…and had no responses it now appears that unless the job is over a thousand pounds a pop they are not even interested to turn out to quote or if it is…expect stupid prices.

    • KennyNovember 9, 2015 at 8:18 am #

      I’m a Carpenter living and working in Cornwall, and have never needed, or wanted to be on these ‘rated tradesman’ type sites. My work, all of it, comes from recommendations. Word of mouth is the best, and most trustworthy advertising.
      From chatting to other tradesmen in the builders merchants, the ones who are on those sites get charged a fortune for the job leads, and as such have to pass it on to their customers. They also said it was so easy to get friends or family to write glowing reports, that any half-wit can become a ‘trusted tradesman’
      Make what you will of that.

      • QuotationCheck AdminNovember 9, 2015 at 10:19 am #

        “They also said it was so easy to get friends or family to write glowing reports, that any half-wit can become a ‘trusted tradesman’
        Make what you will of that.”

        Thanks for sharing your thoughts here on the site.

        I hear you. BUT… what you write may be true of Checkatrade, however Rated People only allow reviews from confirmed customers, i.e the ones that posted job details on their site and were matched to a tradesman. That prevents the type of open manipulation of the reviews/ratings seen on Checkatrade. All checkatrade do is email or phone the “customer” asking if they are genuine!

        All costs are passed onto the customer, whether it’s the cost of Yellow Pages adverts or Rated People job leads. I know several tradeseople who are busy most of the year but in winter their work demand dips so they use Rated People just to keep things ticking over.

        Not every business can rely solely on word of mouth, less established traders for example. Or those wanting to expand rapidly, or break into a new area.

        I feel that these types of review sites can be beneficial to both customers and traders. I used RP to find a local electrician recently and his work was very professional, I guess he knew I would be leaving a review and he didn’t want me to ruin his established reputation on that site.

        I don’t think these kind of sites will ever be a true replacement for word of mouth but they are alternative to Yellow Pages/Newspaper adverts which haven’t worked for years (not for me anyway).

  4. KennyNovember 9, 2015 at 11:42 am #

    I didn’t ask the tradesmen I spoke to which sites they were on, so maybe they were using the more dubious ones. If what you say about Rated people is true then, they have my vote, and I apologise to anyone who might have been thinking twice about using them, after what I said.
    I did advertise in the local paper a few years ago, when I thought things were going to slow down, and I did get a couple of small jobs out of it, but I don’t know anybody, trades or customers, who use the yellow pages. Time it was put out to grass, I think.

  5. End Of TenancyJanuary 13, 2016 at 4:44 am #


    I have used rated people for a full loft insulation and decor and the experience was just great. Even though the tradesmen were punctual and knew their stuff, they still left with many paint damages on several walls brining plaster boards and other stuff in the loft. Over-all experience not so bad as it was good value for money.

    Roofing experience through rated people:
    Then hired a roofer for falling slate tiles and it was a complete waste of time (£150 poorer). Paid another roofer £200 and since I see damp (water patches on the wall)

    Electrical experience:
    2 people came to price the job through word of mouth but their cost was 5 times higher than high street shops. Finally found a decent tradesman for £100 from ratedpeople. Good value for money.

    Windows and doors experience:
    The first guy which came to prove the job was a bit arrogant and rude and had no manners, from ratedpeople. The 2nd person turned out to be a gem!

    I think ratedpeople can be a great place for naive customers like me but perhaps it’s important to do your research via multiple resources “word of mouth included”, “checkatrade” “mybuilder” etc in order to find quality skills

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