Check an insulation company before you renovate

What to check before you pick a contractor for insulation, and what the region and the premiums ask.

4.069 active companies have insulation as their main activity.

KBO, enterprises whose main activity falls under 43.23 · 12 November 2026 · All companies in Installatie van isolatie

Professional competence

There is no separate professional competence for insulation. Still check that the company is active, has an active VAT number and is not bankrupt.

Premiums

For roof and wall insulation the premiums ask for a contractor with VAT. In Wallonia the access to the profession depends on the part: roofing for the roof, structural work for the walls.

By municipality

Main activity, seat or unit

What the premiums ask of the contractor

Flanders: Flanders (Mijn VerbouwPremie): most work only counts when a contractor does it. The invoice shows the contractor’s name, address and VAT number and Belgian VAT, and the contractor fills in a certificate with their enterprise number. No professional competence is required; a heat pump is installed by an installer with a RESCert certificate. The conditions
Wallonia: Wallonia (primes Habitation): the contractor is registered in the KBO and has access to the profession for the work: roofing and waterproofing for the roof, structural work for walls, joinery and glazing for windows, central heating, air conditioning, gas and sanitary for heating. An electric heat pump also needs electrotechnical activities. The conditions
Brussels: Brussels (Renolution): the contractor is registered in the KBO, VAT registered and has access to the profession where the work needs it. Invoices from 2025 and 2026 don’t qualify for a premium for now; the competence rule still applies. The conditions

For 6% VAT on renovation (a home over ten years old), a VAT-registered contractor invoices you directly.

Firmatlas gives no legal advice. Check your premium’s conditions before you sign.

What no register shows

Ask for a written quote with name, address and enterprise number, and compare a few.
Don’t pay a large deposit. Agree on payment in stages as the work progresses.
Ask for the ten-year liability insurance certificate when the work needs an architect.
Ask for references of work nearby and go and look.
Check that the enterprise number on the quote is this company’s.

Questions about checking a contractor

What professional competence does insulation need?

There is no separate professional competence for insulation. Still check that the company is active, has an active VAT number and is not bankrupt.

What does the premium for insulation ask of the contractor?

For roof and wall insulation the premiums ask for a contractor with VAT. In Wallonia the access to the profession depends on the part: roofing for the roof, structural work for the walls.

How do I check an insulation company?

Look the company up above by name or enterprise number and enter the postcode of the work. You see whether it is active, whether its VAT number is active, whether it is not bankrupt and whether it holds the professional competence for the work.

By type of work: Roofer · Structural contractor · Plasterer · Tiler · Joiner · Painter · Heating engineer and plumber · Electrician · Heat pump installer · General contractor · Demolition company