What does it cost to insulate a house?

The cost of fully insulating an average Dutch terraced house (90-120 m2) ranges between €5,000 and €15,000. This includes cavity wall insulation, floor insulation, roof insulation and optionally HR++ glazing. Costs vary significantly by insulation type.

What does cavity wall insulation cost?

Cavity wall insulation costs on average €15 to €35 per m2 including installation. For an average home (70-100 m2 of cavity wall) you pay €1,200 to €3,500. This is typically the cheapest and most effective insulation measure.

How long does it take for insulation to pay for itself?

The payback period varies by insulation type. Cavity wall insulation: 3-6 years. Floor insulation: 5-10 years. Roof insulation: 6-12 years. External facade insulation: 15-25 years. With the ISDE subsidy and rising energy prices, these periods become shorter.

Is it better to insulate from the outside or inside?

External facade insulation is thermally superior: no thermal bridges, the entire cavity is filled. However, it is also more expensive (€80-150/m2) and changes the appearance of the facade. Internal insulation (stud wall) is cheaper but reduces floor space and creates more thermal bridges.

Do I need a permit for facade insulation?

For cavity wall insulation (blown in from outside) you do not need a permit. For external facade insulation (facade panels, render) a planning permit may be required, especially in protected conservation areas or for listed buildings. Always check with your municipality.

Home insulation: what are the costs in 2026?

Q: What subsidies are available for insulation?

Through the ISDE subsidy (Investment Subsidy for Sustainable Energy) from the Dutch government, you receive a contribution for cavity wall insulation, roof insulation and floor insulation, among others. The subsidy amounts to €10-40 per m2 depending on the insulation type. Apply via rvo.nl after the work has been completed.

Cost Overview

Insulation costs by type — 2026

Insulation is the most cost-effective renovation you can undertake. The table below provides an overview of costs per insulation type including installation, excluding subsidies.

Insulation type	Cost per m²	Typical total	Savings/year
Cavity wall insulation	€15 – €35	€1,200 – €3,500	€300 – €600
Floor insulation	€20 – €40	€2,000 – €5,000	€200 – €400
Roof insulation (from inside)	€25 – €55	€2,500 – €7,000	€250 – €500
Facade insulation (external)	€80 – €150	€8,000 – €20,000	€400 – €800
HR++ glazing (per window frame)	€200 – €450	€2,000 – €8,000	€100 – €300

Note: The amounts above exclude the ISDE subsidy. After subsidy, net costs for cavity wall and floor insulation are often 15-30% lower.

Per measure

What does each insulation measure cost?

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Cavity wall insulation

€15 – €35 per m²

Blown-in EPS beads or mineral wool. Cheapest measure, highest return. Completed in 1 day.

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Floor insulation

€20 – €40 per m²

Sprayed PUR foam or insulation boards under the ground floor. Crawl space must be accessible.

🏔️

Roof insulation (from inside)

€25 – €55 per m²

Between and under the purlins. Reduces attic space but relatively affordable. Popular with loft conversions.

🏗️

Roof insulation (from outside)

€60 – €120 per m²

When renewing roof covering. No loss of attic space, thermally superior but more expensive.

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HR++ or triple glazing

€200 – €500 per window frame

HR++ as standard, triple for maximum performance. Including installation per window frame.

🏛

External facade insulation

€80 – €150 per m²

Retrofit insulation with facade panels or render. Best thermal value, changes facade appearance.

Subsidies 2026

What subsidies are available for insulation?

The Dutch government encourages insulation through several schemes. These are the most important ones:

Subsidy	For whom	Amount	Via
ISDE	Owner-occupiers	€10 – €40 per m²	rvo.nl
Warmtefonds	Lower incomes	Interest-free loan	warmtefonds.nl
Energy savings loan	Owner-occupiers	Low interest (1.5–3%)	eigenhuis.nl
Municipal subsidies	Varies by municipality	€200 – €2,000	Your municipality

Smart approach

In what order should you insulate?

Start with cavity walls: lowest cost, fastest payback period, greatest impact on comfort.
Then roof and floor: together responsible for 40-50% of heat loss in a poorly insulated home.
Glazing as a third step: combine with window frame replacement to avoid doing the work twice.
Facade insulation last: most expensive measure — consider this when exterior painting is already planned.
Apply for ISDE afterwards: submit the subsidy application after completion, not before — an invoice is required.

Frequently asked questions

FAQ — Home insulation

A fully insulated terraced house costs on average €5,000 to €15,000. This includes cavity wall, floor, roof insulation and HR++ glazing. Costs vary significantly by insulation type.

Cavity wall insulation costs on average €15 to €35 per m². For an average home you pay €1,200 to €3,500 — this is typically the cheapest and most effective measure.

The ISDE subsidy provides €10–40 per m² back for insulation measures. Apply via rvo.nl after completion. Additionally, there are municipal subsidies and the Warmtefonds for lower incomes.

Cavity wall: 3–6 years. Floor: 5–10 years. Roof: 6–12 years. Facade: 15–25 years. With the ISDE subsidy and rising energy prices, payback periods become shorter.

For cavity wall insulation no permit is needed. For external facade insulation (facade panels) it may be different — check with your municipality, especially in protected conservation areas.

Home insulation: what are the costs?