What does it cost to renovate a dormer?

A dormer does not always need to be completely replaced.
If the basic structure is still sound, renovation can be an economical solution to extend its lifespan and improve comfort.

1. When renovation is worthwhile

Renovation is particularly suitable for:

• Slight wood rot or wear of fascia boards
• Worn roofing
• Poor paint layer or peeling coating
• Outdated window frames or glass
• Insufficient insulation, but a solid construction

2. Average cost estimate (2025)

In case of severe damage or structural problems, complete replacement can sometimes be cheaper than renovation.

3. What determines the price of renovation?

1. Scope of work: The more parts are replaced, the higher the costs.
2. Material choice: Replacing wooden parts with plastic or Trespa increases the price but reduces maintenance.
3. Accessibility: Narrow or difficult-to-reach locations may incur additional labor costs.
4. Extra options: Replacing glass with HR++ or adding ventilation can increase the price.

4. Extending Lifespan

A well-executed renovation can extend the lifespan of a dormer window by 10 to 20 years.
In addition, insulation is often improved directly, which reduces energy costs.

5. Comparison renovation vs. replacement

• Renovation: cheaper, faster and less invasive, suitable if the construction is good.
• Replacement: necessary in case of severe wood rot, subsidence or structural damage.

Guideline:
If more than 50% of the dormer window needs to be replaced, a new dormer window is often more economical.

Conclusion

The average costs for renovating a dormer window in 2025 are:

• Simple maintenance: € 500 – € 1,500
• Partial renovation: € 1,500 – € 4,000
• Full renovation: € 4,000 – € 7,000

A renovation is a good investment if the basic structure is still solid and you want to save costs compared to a new dormer window.

Jeofferte.nl advice:
Always have an inspection carried out by a professional to assess whether renovation or replacement is the best choice.

The total price of a dormer consists of several components.
Below is an indication of the main cost items for a dormer of approx. 3 meters wide.
Prices include VAT, unless stated otherwise.

1. Basic material and construction

• Prefab wooden construction: € 2.500 – € 3.500
• Prefab plastic construction: € 3.000 – € 4.000
• Polyester construction: € 3.500 – € 4.500
• Traditional customisation: more labour-intensive, from € 3.500 for the construction

2. Placement and assembly

• Prefab: € 1,500 – € 2,500 (incl. crane and assembly in 1 day)
• Traditional: € 2,500 – € 4,000 (3 to 5 days of work)

3. Roofing and insulation

• Bitumen or EPDM roofing: € 500 – € 1,000
• Insulation material and vapor-tight layers: € 300 – € 700

4. Window frames and glass

• Plastic window frames incl. HR++ glass: € 1,000 – € 1,500
• Wooden window frames incl. HR++ glass: € 800 – € 1,200
• Extra options (solar control or soundproof glass): + € 250 – € 600

5. Exterior finish

• Standard (wood or plastic): included in basic price
• Luxury finish (Trespa, Keralit, zinc): € 500 – € 1,500 extra

6. Interior finishing (optional)

• Paneling and plasterboard: € 500 – € 1,500
• Plastering and painting: € 500 – € 1,200
• Electrics and lighting: € 200 – € 600

7. Extra options

• Shutters or screens: € 750 – € 1,200 per piece
• Fly screens and ventilation grilles: € 100 – € 250 per window
• Extra insulation: € 200 – € 600

8. Permit and preparation

• Environmental permit: € 200 – € 600
• Construction drawings and structural calculations: € 300 – € 700

Overall picture

Example prefabricated plastic dormer (3 meters wide):

1. Construction: ± € 3,500
2. Assembly: ± € 2,000
3. Roofing & insulation: ± € 800
4. Window frames and glass: ± € 1,200
   Total base: approx. € 6,000 – € 7,000

With extras such as shutters and interior finishing, this can increase to € 8,500 or more.

Conclusion

The costs per component show that:

• Construction and assembly determine the largest part of the price.
• Extra options (shutters, luxury finish) can greatly increase the price.
• Permits and interior finishing must be included separately in the budget.

Jeofferte.nl advice:
Always ask for a specified quote in which these parts are listed separately. This makes a good comparison between providers possible.

The following examples are intended as an indication.
The final price depends on the chosen construction method (prefab or custom-made), the accessibility and the finish.

1. Prefabricated plastic dormer – 3 meters wide

• Material: Plastic (low maintenance)
• Placement: Prefab, rear of the house
• Options: HR++ glass, standard exterior finish
• Total price: approx. € 6,000

2. Prefabricated wooden dormer – 4 meters wide with shutters

• Material: Wood
• Placement: Prefab, rear of the house
• Options: Shutters (2 pieces), HR++ glass
• Total price: approx. € 9,000 – € 10,000

3. Traditional plastic dormer – 4 meters wide

• Material: Plastic
• Placement: Traditional, front of the house (permit required)
• Options: HR++ glass, standard finish, permit and drawings included
• Total price: approx. € 11,000 – € 12,000

4. Luxury polyester dormer – 5 meters wide with screens

• Material: Polyester (seamless, low-maintenance)
• Placement: Prefab, rear of the house
• Options: Screens (3 pieces), ventilation grilles, HR++ glass, luxury upholstery
• Total price: approx. € 14,000 – € 15,500

5. Renovation of existing wooden dormer

• Activities: New roofing, new fascia boards (plastic), painting and HR++ glass
• Width: 3 meters
• Total price renovation: approx. € 3,000 – € 4,500

What influences the differences in these examples?

1. Installation method: prefab is faster and cheaper than traditional custom work.
2. Width: each extra meter adds an average of € 1,200 – € 1,800 to the costs.
3. Material: plastic and polyester are more durable and easier to maintain than wood.
4. Options: roller shutters, screens and luxury finishes incur extra costs.
5. Location: front or street side requires permit and extra work.

Conclusion

In 2025, the following applies to dormers:

• Standard prefab plastic 3 m wide: approx. € 6,000
• Luxury 5 m wide polyester with options: approx. € 15,000
• Renovation can be an interesting alternative if the construction is still good.

Jeofferte.nl advice:
Use price examples as a guideline, but always have a custom quote made based on your specific situation and wishes.

When an existing dormer has structural damage, has subsided or is in poor condition (for example due to wood rot), complete replacement is often more advantageous than an extensive renovation.
Replacing a dormer means that the old dormer is removed and a new one is placed.

1. Average cost indication (incl. removal, disposal and installation of new dormer)

Standard width 3 meters

• Prefab plastic: € 7,000 – € 9,000
• Prefab wood: € 6,500 – € 8,500
• Polyester: € 7,500 – € 9,500
• Traditional custom work: € 8,000 – € 11,000

(Prices include removing old dormer, disposing of waste and installing a new dormer.)

Wider than 3 meters

• 4 meters wide: € 9.500 – € 13.000
• 5 meters wide: € 11.000 – € 15.000

The wider the dormer, the higher the price due to extra material and assembly.

2. What is included in this price?

• Removing the old dormer
• Disposal of rubble and waste
• Placement of the new dormer
• HR++ glass, standard insulation and exterior finish
• Assembly and VAT

3. Not included (depending on the situation)

• Interior finishing (panelling, plastering, painting)
• Shutters or screens
• Luxury exterior finish (trespa, zinc)
• Permit costs and building drawings

4. Extra costs

5. When to replace and when to renovate?

• Renovation: for minor damage or wear (e.g. roofing, painting, window frames).
• Replacement: for severe wood rot, cracks, subsidence or if more than 50% of the dormer needs to be renewed.

Rule of thumb:
Is the dormer older than 25-30 years and in poor condition? Then complete replacement is almost always more advantageous and sustainable.

6. Factors influencing the replacement price

1. Width and height of the new dormer
2. Material choice (wood, plastic, polyester)
3. Location (front with permit or back permit-free)
4. Extra options and finishing
5. Accessibility of the roof

Conclusion

In 2025, the costs for replacing a dormer window will average between:

• 3 meters wide: € 6,500 – € 9,500
• 4 meters wide: € 9,500 – € 13,000
• 5 meters wide: € 11,000 – € 15,000

Extra options and luxury finishes can increase this amount.

Jeofferte.nl advice:
Always request multiple specified quotes so that the costs for removal, disposal and placement are clear and there are no surprises.

When installing a dormer, there are several options to increase comfort, appearance, and durability.
These extras increase the price, but can add convenience and value in the long run.

1. Shutters or Screens

Function:

• Protection against sun, heat and privacy.
• Extra insulation in winter months and blackout for bedrooms.

Costs:

• Shutter or screen: € 750 – € 1,200 per piece (depending on size and design).

2. Mosquito Nets and Ventilation Grilles

Function:

• Better ventilation and protection against insects.
• Especially popular in bedrooms and workspaces.

Costs:

• Mosquito screens: € 100 – € 250 per window.
• Ventilation grille: € 100 – € 200 each.

3. Luxury Cladding

Materials:

• Trespa, Keralit, zinc or aluminum.

Advantages:

• Durable finish, luxurious appearance and very low maintenance.

Costs:

• Luxury cladding: € 500 – € 1,500 extra, depending on material and surface area.

4. Glass Options

• HR++ glass: standard for modern dormers, very insulating.
• Solar control glass: keeps heat out in the summer.
• Soundproof glass: ideal for busy roads or cities.

Costs:

• Solar control or soundproof glass: € 250 – € 600 extra.

5. Interior Finishing

Options:

• Finishing with plasterboard or MDF
• Plastering and painting
• Electrical points, sockets and lighting

Costs:

• Interior finishing: € 1,000 – € 2,500, depending on the chosen finish and amenities.

6. Extra Insulation

• Additional insulation of walls, frames and roof parts.
• Helps in achieving energy saving goals.

Costs:

• Extra insulation: average € 200 – € 600, depending on the size.

7. Custom color and finish

• Different color scheme for frames and exterior cladding.
• Ensures a better match with the style of the house.

Costs:

• Depending on the material and the chosen color combination.

Conclusion

Key additional options affecting the price:

1. Shutters or screens
2. Mosquito nets and ventilation grilles
3. Luxury cladding (trespa, zinc)
4. Sun-resistant or soundproof glass
5. Interior finishing and electricity
6. Extra insulation and color options

Jeofferte.nl advice:
Extra options are most cost-effective when installed directly with the installation of a new dormer window. Adding them later is often more expensive.

A dormer is an investment that adds a lot of value to a home.
By thinking carefully about the points below in advance, you avoid surprises and make a choice that suits your wishes and budget.

1. Purpose and use of the space

• What purpose does the space have? Bedroom, office, bathroom or playroom?
• Finishing and insulation must be tailored to the use.

2. Placement location and permit

• Back side: often permit-free with standard dimensions.
• Front or public side: almost always subject to permit.
• Stricter rules apply to monuments or protected townscapes.

3. Width and Height

• The wider and higher, the more space, but also the higher the price.
• Determine in advance which dimensions are functionally and aesthetically desirable.

4. Material Choice

• Wood: classic and cheaper, but more maintenance.
• Plastic: low-maintenance and durable.
• Polyester: seamless, luxurious and very easy to maintain.

5. Prefabricated or traditional customization

• Prefabricated: faster placement and more affordable, suitable for standard roofs.
• Traditional: customization, suitable for complex situations and specific wishes.

6. Extra options

Consider directly during placement:

• Roller shutters or screens
• Sun-resistant or soundproof glass
• Insect screens and ventilation grilles
• Luxury upholstery or finishing

Ordering together with placement is more advantageous than adding afterwards.

7. Interior finishing

• Do you want a shell dormer and finish it yourself, or delivered ready-made?
• Take into account costs for stucco, painting and electricity.

8. Budget and total costs

• In addition to the purchase price, there are additional costs such as:
• Permit and drawings
• Possible roof reinforcement
• Finishing and extra options
• Make a total budget in advance including all costs.

9. Warranty and quality marks

• Preferably choose a supplier with KOMO-keur, BouwGarant or other quality labels.
• Ask about warranty conditions for both the product and the assembly.

10. Future Value and Maintenance

• A well-planned dormer increases the property value and living comfort.
• Consider future maintenance costs when choosing materials.

Conclusion

A dormer provides a lot of light, space and value, but it is important to make clear choices in advance in:

1. Location and permit
2. Dimensions and material
3. Installation method
4. Options and finishing
5. Budget and planning

Jeofferte.nl advice:
Combine good preparation with requesting multiple specified offers to make the best choice.