Cost of installing roof insulation
Roof insulation costs 2026
The costs for roof insulation range from €25 to €150 per square metre, depending on the chosen material and the insulation method. Roof insulation involves applying insulation material to your roof to prevent heat loss. This is an important investment because approximately 30% of heat leaves your home through the roof. In this price guide, you can read about the costs of roof insulation and what to consider when insulating your roof.
Table of Contents
- What does roof insulation cost?
- Roof insulation costs per insulation material
- Price-determining factors for roof insulation
- Extra costs and surcharges for roof insulation
- How does the professional work during roof insulation?
- How can you save on roof insulation?
- Why is roof insulation necessary?
- Find the best professional for roof insulation
- Frequently asked questions about roof insulation
- Book a professional for roof insulation
- Useful links
What does roof insulation cost?
The costs for roof insulation on the inside average between €25 and €60 per square metre including installation. This makes roof insulation one of the most cost-effective investments for your home, with a payback period of 3 to 7 years through lower energy costs. The exact price depends on the type of insulation material you choose and whether you insulate the roof from the inside or the outside.
Roof insulation costs inside per type
| Type | Material costs per m² | Costs per m² incl. installation |
|---|---|---|
| Stone wool/Rock wool | €20 | €50 |
| Glass wool | €10 | €25 |
| Insulation boards | €12 | €35 |
| PUR foam | N/A | €30 |
| Sheep wool | €25 | €35 |
| Cork | €30 | €60 |
| Paper flakes (cellulose) | €18 | €25 |
The table shows that glass wool is the most affordable option at €25 per square metre including installation, while cork at €60 per square metre is at the top end. Paper flakes offer a good balance between price and sustainability.
Roof insulation costs outside
| Description | Costs per m² |
|---|---|
| Installation insulation outside | €40-60 |
| Installation insulation outside incl. replacing roofing | €150 |
For insulation on the outside of a flat roof, you pay €40 to €60 per square metre for just the insulation. If the roofing also needs to be replaced, this increases to €150 per square metre. Outside insulation is more expensive due to the extra work, but often more effective for inaccessible attics.
All mentioned prices include 21% VAT and labour from the affiliated professionals.
Roof insulation costs per insulation material
The costs for roof insulation are mainly determined by your choice of insulation material and whether you insulate the roof from the inside or the outside. Glass wool is the most affordable option at €25 per square metre including installation, while cork at €60 per square metre serves the higher segment.
| Insulation material | Material costs per m² | Total price per m² incl. installation |
|---|---|---|
| Glass wool | €10 | €25 |
| Paper flakes (cellulose) | €18 | €25 |
| Stone wool/Rock wool | €20 | €50 |
| Insulation boards | €12 | €35 |
| PUR foam | N/A | €30 |
| Sheep wool | €25 | €35 |
| Cork | €30 | €60 |
| Insulation outside | N/A | €40-60 |
| Insulation outside incl. roofing | N/A | €150 |
Price-determining factors for roof insulation
The costs for roof insulation that you ultimately pay depend on several factors. The chosen material is just one part of the price. The nature of the work, the accessibility of the roof, and the timing of the job also play a major role.
Type of roof
Insulating a pitched roof requires different techniques than a flat roof. With a pitched roof, work is usually done between the rafters, which requires more precision. For a flat roof, the costs are often higher because the insulation is often applied to the outside, which involves extra preparatory work.
Choice of insulation material
Glass wool is cheap to purchase but labour-intensive to install because it must be cut to size and carefully fitted. Insulation boards or PUR foam are more expensive in terms of material but faster to process, resulting in lower labour costs. The balance between material and labour costs determines the total costs.
Surface area
The larger the surface area to be insulated, the higher the total costs. At the same time, larger surfaces often benefit from economies of scale. The professional can work more efficiently and materials are purchased more cheaply for larger volumes, reducing the price per square metre.
Accessibility of the roof
If the roof is difficult to reach, for example, due to a narrow staircase or limited access to the attic, this costs extra time. The professional must bring materials up in multiple trips and sometimes take extra safety measures, which increases the labour hours and thus the costs.
Complexity of the construction
Roofs with many corners, chimneys, skylights, or other obstacles require more custom work. The insulation material must be cut exactly to size and finished well around penetrations. This makes the work labour-intensive and increases the total costs.
Additional work
If the ceiling needs to be finished again with plasterboard after applying insulation, or if the roofing must be removed and replaced during outside insulation, the costs increase significantly. These extra actions sometimes double the labour time.
Urgency
Urgent jobs are more expensive than planned work. The professional must adjust their schedule, which costs them revenue elsewhere. This missed time is reflected in the price of the urgent job.
Weekend and evening hours
Work during the weekend or in the evenings costs more than during the week. This is due to surcharges that apply to work outside regular hours. Therefore, preferably plan your job during the week.
Region
Prices are often higher in large cities than in rural areas. This is due to higher hourly wages and more expensive material delivery in urban areas. The region you live in therefore influences the costs.
Preparation and accessibility
If the attic is full of belongings or the roof is not directly accessible, the professional must first spend time clearing or waiting while you do this. Ensure the workspace is clear before the professional arrives to avoid unnecessary costs.
Combining with other jobs
If you combine several insulation projects, such as floor insulation and roof insulation at once, the professional can work more efficiently. They only need to come once and can purchase materials collectively, which saves costs.
Postponement of maintenance
Addressing small problems early prevents higher heating costs and larger investments later. A poorly insulated roof lets heat escape year after year, causing your energy bill to rise. Investing early in insulation pays off faster.
Extra costs and surcharges for roof insulation
Extra costs for roof insulation are situation-dependent. At Zoofy, you do not pay call-out charges.
- Urgent jobs: A surcharge applies to urgent jobs because the professional must adjust their schedule
- Weekend work: Work during the weekend is more expensive than during the week
- Ceiling finishing: If you want the attic ceiling finished after insulation, additional costs will apply
- Removing and replacing roofing: For insulation on the outside, this can cost up to €150 per square metre
- Difficult accessibility: Extra costs may be charged if the roof is hard to reach
How does the professional work during roof insulation?
Roof insulation follows a fixed set of steps, depending on the type of roof and the chosen insulation method.
- Inspection and preparation: The installer inspects the roof and determines the best insulation method based on the type of roof (flat or pitched) and the desired insulation value. They also calculate the costs and discuss these with you.
- Preparing the workspace: The attic is cleared so the professional can work safely. For outside insulation, the roofing is first removed. Ensure the workspace is accessible and empty before the technician arrives.
- Applying insulation material: The chosen insulation material (glass wool, stone wool, PUR foam, or insulation boards) is professionally applied between or on the rafters. For insulation from the inside, the material is cut to size and carefully fitted.
- Installing a vapour barrier: A vapour barrier is applied to the inside to prevent moisture problems. This protects the insulation and prevents condensation.
- Finishing: For inside insulation, the ceiling can be finished with plasterboard. For outside insulation, the roofing is replaced or renewed. The job lasts from one day for a small attic to several days for complete roof insulation.
How can you save on roof insulation?
There are several ways to reduce roof insulation costs without compromising on quality.
- Address draughts early: Small insulation problems or draughts cause heat loss and higher heating costs year after year. By addressing them early, you prevent larger investments later and save on your energy bill.
- Clear the workspace: Ensure the attic or roof is accessible and empty before the professional arrives. This saves labour time and costs because the installer can start immediately.
- Plan during the week: Weekend surcharges and urgent rates significantly increase the price. By planning your job on a weekday, you save on these extra costs.
- Combine with roof renovation: If you are already having the roofing replaced, it is smart to insulate at the same time. This way you only pay once for removing and replacing the roof.
- Book via Zoofy: You get a fixed price in advance, without call-out charges and without surprises. You only pay after completion of the job.
Why is roof insulation necessary?
Roof insulation is necessary because approximately 30% of heat leaves your home through the roof.
Uninsulated roof
An uninsulated roof lets heat escape directly outside, causing your heating costs to be structurally higher. In winter you lose heat and in summer the attic heats up excessively, affecting the comfort in your entire home.
Outdated insulation
Old insulation loses its effectiveness through years of use. The material sags, moisture can cause damage, and the insulation value drops. This results in higher energy costs and a less comfortable indoor climate, comparable to an uninsulated roof.
Find the best professional for roof insulation
Roof insulation must be professionally installed to prevent moisture problems and thermal bridges.
- No call-out charges: At Zoofy, you never pay extra for the professional's arrival.
- Fixed price in advance: You know exactly what the costs are before the job begins, without surprises afterwards.
- Quick booking: Choose a time and book a professional directly, no cumbersome quote rounds.
- Payment via QR code after completion: You only pay when the work is finished and you are satisfied with the result.
- Reliable, verified professionals: All affiliated professionals are carefully selected and verified.
- Professional installation: A reliable installer ensures that the insulation fits correctly, achieves the right insulation value, and no thermal bridges occur.
Frequently asked questions about roof insulation
What does roof insulation cost per m²?
The costs for roof insulation are between €25 and €60 per square metre for insulation on the inside, including installation. Glass wool is the cheapest option at €25 per square metre, while cork at €60 per square metre is at the top end. For insulation on the outside of a flat roof, you pay €40 to €60 per square metre, or up to €150 per square metre if the roofing also needs to be replaced.
What is the payback period for roof insulation?
On average, you earn back the investment in roof insulation within five to six years through lower heating costs. This is because approximately 30% of heat moves through an uninsulated roof. With good insulation, your energy costs drop structurally, allowing the investment to pay back quickly.
How many degrees does roof insulation matter?
Roof insulation can improve the temperature difference in the attic by 3 to 5 degrees. In winter the heat stays inside and in summer the attic heats up less. This increases comfort throughout your home and lowers your heating costs all year round.
What does it cost to insulate a pitched roof?
Insulating a pitched roof costs an average of €25 to €60 per square metre, depending on the chosen material. Inside insulation with glass wool costs €25 per square metre, while stone wool costs about €50 per square metre including installation by the affiliated professionals.
Is inside or outside insulation better?
Outside insulation has a higher insulation value without thermal bridges but costs more. Inside insulation is cheaper and more accessible, but slightly less effective. The choice depends on your budget and the accessibility of your attic.
Do I need to install a vapour barrier with roof insulation?
Yes, for insulation on the inside, a vapour barrier is necessary to prevent moisture problems. The vapour barrier protects the insulation against condensation and prevents damage to the structure.
Can I install roof insulation myself?
Inside insulation with glass wool or insulation boards can be done yourself if you have DIY experience. Outside insulation and PUR foam (polyurethane foam) require a professional due to the complexity and specialised material.
How long does it take to insulate a roof?
Insulating an average attic takes one to two days. Outside insulation can take several days, depending on the surface area and whether the roofing is also being replaced.
Are there subsidies for roof insulation?
Yes, ISDE subsidies (Investment Subsidy for Sustainable Energy) and municipal schemes are often available for home insulation. Check the current conditions at RVO or your municipality to see if you qualify.
Can I combine roof insulation with solar panels?
Yes, but plan this carefully. With outside insulation, the roofing must be removed, which is a good moment to carry out both improvements at once and save costs.
Book a professional for roof insulation
Ready to have roof insulation installed? At Zoofy, you book a professional directly, without quotes and without call-out charges. You see exactly what the costs are in advance, and Zoofy connects you with a reliable, verified professional. You only pay when the work is done.