Everything you need to know about a 4-meter dormer

A dormer of 4 meters wide offers a lot of extra living space and light and is often chosen for an attic that will be used entirely as a bedroom or workspace.
The price depends on the type (prefab or custom), material and finish.

1. Price indication 4 meters wide (including installation and VAT)

Prefab dormer – 4 meters wide

• Wood: € 6,500 – € 8,500
• Plastic: € 7,000 – € 9,000
• Polyester: € 7,500 – € 10,000

Traditional (custom) dormer – 4 meters wide

• Wood: € 8,000 – € 10,000
• Plastic: € 8,500 – € 11,000

2. What is included in this price?

• Construction and placement
• HR++ glass and insulation
• Exterior finish (standard)
• VAT and assembly costs

3. Not included (optional)

• Shutters or screens
• Permit costs
• Interior finishing (plastering, painting, electricity)
• Extra insulation options or custom frame designs

4. Extra options and their influence on the price

A 4-meter wide dormer with shutters and luxury finish can therefore increase to € 11,000 – € 13,000.

5. Example Calculations

Example 1 – Prefabricated plastic (standard)

• Width: 4 meters
• Back of house
• Including HR++ glass, standard finish
• Total price: approx. € 8,000

Example 2 – Traditional wooden version

• Width: 4 meters
• Front of house (incl. permit)
• Including painting and bargeboards
• Total price: approx. € 9,500 – € 10,000

Example 3 – Luxury polyester dormer with extra options

• Width: 4 meters
• Including shutters, mosquito nets and luxury finish
• Total price: approx. € 11,500 – € 13,000

6. Factors that influence the price

1. Type of placement: prefab (faster and cheaper) or custom (more freedom).
2. Material choice: wood, plastic or polyester.
3. Location: front often requires a permit.
4. Options: shutters, mosquito nets, ventilation, special finish.
5. Accessibility: assembly with crane and workspace around the house.

Conclusion

A dormer of 4 meters wide costs on average in 2025:

• Prefab: € 7,000 – € 10,000
• Traditional custom work: € 8,500 – € 11,000

With luxury options and finishing, this can amount to € 13,000.

Jeofferte.nl advice:

• Request customized quotes with clear specifications.
• Consider ordering options directly to avoid double costs.

The price of a dormer is custom-made. Various aspects together determine the final costs.

1. Placement method: prefab or traditional

• Prefab dormer:
• Made in the factory and placed in one day with a crane.
• Faster and often more affordable.
• Traditional dormer:
• Custom-built on site.
• More expensive due to more labor hours, but suitable for special situations.

2. Width and height

• The larger the dormer, the higher the costs.
• Each extra meter of width costs an average of € 1,200 – € 1,800 extra.
• A wider dormer provides more space and light, but requires more material and labor.

3. Material choice

• Wood: cheaper to purchase, requires more maintenance.
• Plastic: low maintenance, slightly more expensive.
• Polyester: seamless and very low maintenance, higher price range.

4. Location and permit

• Rear or non-public side: often permit-free.
• Front: permit and extra costs for drawings and fees.
• Monuments and protected cityscapes always have extra rules.

5. Extra options and finishing

Options that increase the price include:

• Shutters or screens
• Mosquito nets and ventilation grilles
• Luxury finishing (trespa, zinc)
• Solar or soundproof glass

6. Roof Accessibility

• Placement with crane: requires space and may incur additional costs for hard-to-reach locations.
• In narrow streets or courtyards, a small crane or manual placement may be necessary.

7. Interior Finishing and Insulation

• Finishing on the inside (plasterboard, painting, electricity) is not always included in the standard price.
• Extra insulation can increase the price, but improves comfort and energy saving.

8. Season and Planning

• In the spring and summer, waiting times are longer and the chance of a discount is smaller.
• In the winter period, there are often shorter waiting times and more room for negotiation.

Conclusion

The main cost determinants for a dormer in 2025 are:

1. Type of placement (prefab or traditional)
2. Dimensions (width and height)
3. Material (wood, plastic or polyester)
4. Location and permit
5. Extra options and finishing
6. Accessibility of the roof
7. Interior finishing and insulation

Jeofferte.nl advises:
Always request multiple specified quotes so that it is clear which work and materials are included in the price.

Installing a dormer is an investment that requires customization.
The following steps significantly reduce the chance of surprises in the final price.

1. Determine your goal and wishes

• Do you mainly want more light, more living space, or both?
• Will the space be used as a bedroom, office, or bathroom?
• Which look suits your home (modern or classic)?

Tip: Make a list of wishes and requirements in advance.

2. Have the current situation assessed

• Measure the available roof width and check the type of roof.
• Have a professional look at the structural strength of the roof.
• Reinforcement may be necessary for older homes; this affects the price.

3. Choose the type of dormer

• Prefab: fast, more affordable and suitable for standard situations.
• Traditional: custom, more flexibility in dimensions and finish.

4. Select the material

• Wood: more affordable, but requires maintenance.
• Plastic: low maintenance and popular.
• Polyester: seamless, luxurious and very durable.

5. Check if a permit is required

• Back: often permit-free with standard dimensions.
• Front or side: usually requires a permit.
• Consider fees and costs for drawings.

6. Choose desired extra options

• Shutters or screens
• Sun-resistant glass
• Luxury finish (trespa or zinc)
• Interior finishing (gypsum, painting, electricity)

Advice: Order options directly; adding them later is more expensive.

7. Request multiple specified quotes

• Compare at least three quotes.
• Pay attention to the specification of material, assembly, options and additional costs.
• Also look at warranty conditions and quality marks of the company.

8. Plan the right moment

• In the autumn and winter there are often shorter waiting times and sometimes sharper prices.
• Take into account a delivery time of 6 to 12 weeks.

9. Have the quote checked

• If in doubt, have an expert assess the quote.
• Ask for a final price agreement before work starts.

Conclusion

A good cost estimate for a dormer is achieved by:

1. Preparation and clarity about wishes.
2. Checking the roof construction and permit requirement.
3. Multiple specified quotes and timely planning.

Jeofferte.nl advises:
Follow this step-by-step plan and choose a specialist with experience and quality marks. This will give you a reliable cost overview and prevent additional work afterwards.