Will you soon enjoy more space and light in your attic? Fitting a dormer not only increases your living comfort, but also the value of your house. Curious about the costs and what to look out for when having a dormer window installed?
What does it cost to have a dormer window installed?
Dormer window prices depend on your specific wishes, such as the size, the material and whether you opt for prefab or traditional installation. Map out your wishes so you can better estimate the costs. In the overview below, you will find the average dormer installation costs for a standard size (1.5 metres high x 2.5 metres wide).
| Prefab | Traditional | |
|---|---|---|
| Wood dormer | from £8.500 | from £9,000 |
| Plastic dormer | from £6,500 | from £7,000 |
| Polyester dormer | from £7.000 | – |
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What will installing a dormer do for you?
A dormer window increases your living comfort and transforms that dark or awkward space in your house into a beautiful, spacious room. The finest benefits are:
- Extra light:A dormer window allows more light to enter your room. Light makes you more productive, warms your room naturally when the sun is shining and makes the room appear visually larger.
- Extra space:In addition to extra light, a dormer window also creates extra space. This allows you to make the most of the space and creates more standing room.
- Increase the value of your home:The installation of a dormer window will increase the value of your home. A nice bonus if you sell your house.
Can you install a dormer without a permit?
Yes, under certain conditions you can have a permit-free dormer placed. The government stipulates the following requirements for this:
- The dormer has a flat roof
- The dormer does not face publicly accessible areas (a road, green or waterway, for example)
- Maximum height of the dormer is 1.75 metres
- Placement of the dormer at least 0.5 metres from the top, side and bottom of the roof.
Do you want to place a dormer and do not meet all the above conditions? The zoning plan and the aesthetics requirements of your region will then determine whether the permit will be granted. Check with your municipality or do the permit check at the Omgevingsloket. You can also apply for a permit on that website.
How will a dormer be installed?
Based on the dimensions and preferences you have provided, the dormer will be manufactured. A specialist will then set to work installing the dormer on your roof. With a prefabricated dormer this can be done within one day, a traditional dormer is usually assembled within a few days.
1. Preparatory work
As soon as you have agreed with the specialist what the dimensions and materials will be, we will check whether a permit is needed. If this is not necessary, or if the permit has been granted, the dormer will be ordered. The dormer specialist will be happy to advise you on the type of dormer that will match your home.
2. Installation of the dormer
After production, it is time to install the dormer. The dormer specialist first makes the necessary preparations on site. For example, he will lay tarpaulin in the attic to protect the floor. A hole is created in the roof according to the dimensions of the dormer window. The roof covering, any insulation material and other construction waste are removed immediately.
Then it is time to actually install the dormer window. A prefabricated dormer window comes ready-made and only needs to be lifted onto the roof with a crane. A traditional dormer is delivered in pieces. It will be lugged up the stairs or a ladder, for example, and assembled exactly to fit the roof.
As soon as the dormer is in place, the finishing touches will be added. Finally, the specialist will check whether everything has been assembled safely and correctly, to avoid future problems such as leaks or draughts.
Make a prefab dormer window or build it on site?
Most people choose to make a prefab dormer window. Prefab means that your dormer leaves the factory ready-made and is placed on your roof in one go. For this, the dormer specialist uses a crane.
Do you live in a street where no crane fits? Or is your house older and not everything is straight anymore? Then choose a traditional variant. It is delivered in pieces and assembled on site. No large equipment is needed and the dormer can be fitted onto your roof exactly as it is. A traditionally fitted dormer involves higher costs than a prefabricated one. This is partly because this variant takes more time to install.
What material will you go for?
If you have a dormer window installed, you have a choice of materials: plastic, polyester or wood. In the overview below you will find characteristics of each material.
| Material | Characteristics |
|---|---|
| Plastic | – affordable – low maintenance – weatherproof |
| Polyester | – moulded to size, therefore seamless and leakage-free – high insulation value – low maintenance |
| Wood | – authentic look – easy to work with – regular maintenance required |
Tips for installing a dormer window
When installing a dormer window, it is important to make well-considered choices, so that you can enjoy your dormer window for many years. To help you, here are three tips.
1. Be well informed
There are many choices to be made when deciding on your ideal dormer window. Think about the type of roofing, degree of insulation, type of windows and type of glass, etc. So get advice from an experienced specialist. Being well informed will ensure you make the right choice.
2. Check quality marks
You obviously want to have a good, high-quality dormer installed. There are several quality marks that give you that extra bit of assurance of quality and/or service.
- KOMO: KOMO is an important quality mark in the Dutch construction industry. They test and approve products and building processes. If your dormer bears the KOMO quality mark, then you know that the material of your dormer has been thoroughly tested.
- BouwGarant: BouwGarant is also a major quality mark in the Dutch construction industry. If your dormer specialist is a member of Bouwgarant, they are regularly tested and must meet all requirements in terms of quality, reliability, workmanship and service.
- VKG: Are you opting for a dormer window with plastic frames? Suppliers affiliated to VKG work with strict quality requirements for plastic window frames. This ensures high-quality and durable window frames with guarantee periods of up to 10 years.
- FSC and Keurhout: Are you opting for a wooden dormer window? These labels indicate that the wood used in your dormer is legal, socially responsible and sustainably produced.
3. Make clear agreements and record them
Have you requested dormer window quotes and compared them? Put all agreements made with the chosen specialist on paper to avoid any unpleasant situations afterwards. Think about all the costs (including VAT and call-out charges), the down payment, the products and services you purchase but also the service afterwards, including warranty. This can be done by e-mail, in writing or via a renovation agreement. Walk through everything together after the installation.
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Frequently asked questions
After the dormer has been assembled in the factory, a prefabricated dormer window will be installed on your roof within 1 day. Do you have your dormer assembled on site?
The cost of a dormer depends on the choice of materials and dimensions, among other things. A plastic dormer starts at £6,500 for a 2.5-metre width. Going for wood? Then costs start on average at £8,500 for the same dimensions.
Not always. You can install a dormer without a permit if you meet the government’s conditions. These include a dormer with a flat roof and not facing public areas, with a maximum height of 1.75 metres. In doubt? The Omgevingsloket’s permit check can help you with this.
