Insulation Grant 2026: Amounts, Mistakes and Real Applications

Short answer: the insulation grant in 2026 typically ranges between €500 and €4,000. The exact amount depends on the type of insulation, the number of measures, and the number of square metres. In practice, we see many applications miss out on money due to errors or incorrect choices. On this page, you will find real-life examples, common mistakes, and how to get it right.

Do you want to know immediately how much grant you will receive? See applying for an insulation grant.

Real-life Examples of Insulation Grants

Practical examples based on recent projects. Actual amounts may vary.

Case 1 - Mid-terrace house (ground floor + intermediate floor, thought this would qualify for a grant)

• Investment: €6,800

• Expected grant: €1,800

• Grant received: €900 (intermediate floor is excluded from ISDE - only floor above crawl space counts)

• Net cost: €5,000

Lesson: intermediate floor insulation (between storeys) does not qualify for ISDE grant, even though it greatly improves comfort and sound. Always check the registration codes and the building component in advance.

Case 2 - Corner house (roof insulation)

• Investment: €8,100

• Grant: €975

• Net cost: €7,125

Case 3 - Detached house (3 measures)

• Investment: €18,500

• Grant: €4,195

• Net cost: €14,305

The 7 Biggest Mistakes with Insulation Grants

1. Insulating too few square metres

2. Not meeting the minimum insulation value

3. Self-installation without an accredited company

4. Invoices that do not meet the requirements

5. Applying too late

6. Only taking one measure

7. Incorrect combination of measures

Want to avoid these mistakes? Have your grant calculated and applied for.

Grant per Insulation Measure

ISDE Rates 2026 per m² (or per item)

For 2 or more measures, the basic grant is doubled. If you opt for biobased insulation (cellulose, wood fibre, hemp, flax, cork, sheep's wool, straw), an additional biobased bonus per m² is added.

Intermediate floor insulation (between storeys) is not eligible for ISDE grant. Only floors above an unheated space (such as a crawl space) count.

Example Calculation: Roof + Cavity + Biobased

Assume: 80 m² roof insulation + 50 m² cavity wall insulation, both with biobased material:

• Roof: 80 × €37.50 = €3,000
• Cavity: 50 × €12.00 = €600
• Total grant: €3,600

For two measures, the grant per m² often increases significantly.

What Almost Nobody Tells You About Insulation Grants

A grant does not automatically make insulation the best choice. In some situations, the payback period is still long, or other measures are more sensible. In practice, we sometimes advise not to apply for a grant, for example, for small areas or unfavourable housing conditions.

Is Insulation Still Profitable Without a Grant?

That depends on the situation.

• With grant: lower investment and faster payback period.

• Without grant: sometimes still profitable, but less attractive.

Have your situation calculated before you decide.

Step-by-Step Grant Application

1. Check if your home is suitable

2. Choose one or more insulation measures

3. Have insulation carried out by a specialist

4. Collect invoices and proof

5. Apply for a grant via the RVO

How Long Does an Insulation Grant Take?

• Implementation: project-dependent

• Application: approximately 1 hour

• Payment: usually 4 to 12 weeks

Delays often occur due to incorrect or incomplete documents.

Apply Yourself or Have It Done?

Apply Yourself

• No extra costs

• Higher chance of errors

Via a Specialist

• Greater chance of maximum grant

• Less risk and less work

See how we arrange grant applications for you.

Hidden Costs of Insulation

• Consultancy fees

• Additional insulation requirements

• Modifications to the home

• Delays

These costs are often not included in calculations but do affect profitability.

Checklist: Do You Qualify?

• You own the property

• The property is older than 2 years

• The insulation is carried out by a company

• You meet minimum surface area requirements

• You meet the insulation values

If you meet these conditions, there is a good chance you will receive a grant.

Honest Advice

Not every home is suitable for insulation with a grant. In some cases, it is not financially or technically advisable. We therefore also advise when it is better not to do it.

Have your situation assessed without obligation.

Frequently Asked Questions About Insulation Grants

How much grant do you get for insulation in 2026?

Usually between €500 and €4,000, depending on the type of insulation, surface area, and number of measures.

Which insulation provides the most grant?

Roof insulation generally yields the highest grant per square metre.

Do you have to take two measures?

Not mandatory, but it usually increases the grant per m².

Can you get a grant if you insulate yourself?

No, the work must be carried out by an accredited company.

How long does a grant application take?

On average 4 to 12 weeks until payment after application.

What goes wrong most often?

Errors in invoices, insufficient insulation value, and too little surface area.