Mandatory home audit for a heat pump — costs and process 2026
In 2026, the energy audit is required to unlock the highest heat pump grants in Wallonia and Brussels. Depending on the type of audit (home audit, PAE2 or EPC certificate), the cost ranges from 250 to 1 200 € — but a specific audit grant can significantly reduce that amount. Here’s the full picture.
Indicative 2026 costs. The exact amount depends on the floor area of the home, its complexity and the accredited auditor appointed.
Price of an energy audit in 2026 by type and floor area
The costs below are incl. VAT, for a home located in Wallonia or Brussels. The deductible audit grant can cover 50 to 100 % of the cost depending on the income category. The auditor must be accredited by the Public Service of Wallonia (SPW) or the Brussels Region.
| Type of audit | Small home up to 150 m² | Medium home 150–250 m² | Large house over 250 m² |
|---|---|---|---|
| Accredited home auditmandatory for high heat pump grant amounts | 750 € | 950 € | 1 200 € |
| PAE2 reportenergy action plan · Wallonia | 600 € | 750 € | 900 € |
| EPC certificatebuilding energy performance | 250 € | 380 € | 500 € |
These amounts are indicative ranges. The audit grant can cover up to 100 % of the cost for low-income households. See also the full heat pump prices page.
What determines the audit requirement for your heat pump grant
The energy audit isn’t always required, but it becomes mandatory as soon as you target the highest grant amounts or a full-renovation programme. Here are the six key factors to know.
- When the audit is mandatory
In Wallonia, the accredited home audit is required for low and middle-income households wishing to benefit from the highest amounts of the heat pump Prime Habitation (cat. B and M). Without an audit, the grant is capped at the "reduced" amount.
- SPW-accredited auditor required
The audit must be carried out by a certified auditor on the official list of the Public Service of Wallonia. A report produced by a non-accredited firm will not be accepted when processing the grant file.
- Content of the PAE report
The PAE report (Energy Audit Protocol) details the thermal state of the home, recommends works in order of priority and establishes the expected performance gain. The heat pump must appear in the recommendations for the grant to be valid.
- Income categories and the audit
Low-income households (cat. B) can obtain an audit grant covering up to 100 % of the cost. For middle incomes (cat. M), the coverage reaches 75 %. High incomes (cat. E) generally do not benefit from specific support for the audit.
- Validity period of the audit
An accredited home audit is valid for 5 years. If a recent audit (less than 5 years old) has already been carried out on the home, it can be reused for the heat pump grant file without ordering a new one.
- Deductible audit grant
The energy audit grant is a grant separate from the heat pump grant: it directly funds the cost of the audit and can be combined with the Prime Habitation. At wendows, we build this grant into the overall assembly of your file.
All heat pump grants →
Audit grant and grants linked to the heat pump audit
The energy audit qualifies for a specific grant that reduces its net cost. It also unlocks the highest amounts of the Prime Habitation Wallonia for your heat pump.
Energy audit grant — home audit
The Walloon audit grant funds the cost of the accredited home audit: up to 750 € for low-income households (almost the entire cost for a small home), and up to 550 € for middle incomes. This grant is combined with the heat pump Prime Habitation.
- Audit carried out mandatorily by an SPW-accredited auditor
- PAE or PAE2 report delivered in the regulatory format
- Application to be filed within 2 years of receiving the report
Heat pump Prime Habitation unlocked by the audit
Without an audit, the air-to-water heat pump grant is capped at a reduced amount. With an accredited home audit, low and middle-income households access the full amount: up to 4 000 € for an air-to-water heat pump and up to 6 000 € for geothermal.
- Audit mandatory for the full "cat. B / M" amount
- COP ≥ 3.5 (air-to-water heat pump) or COP ≥ 4.0 (geothermal)
- Replacement of fossil heating required
We organise the audit and build the complete file
wendows identifies an accredited auditor, coordinates the visit, builds the audit grant into the financial assembly and deducts all grants directly from your final bill.
- Check on the audit requirement
We analyse your situation: current heating type, income category, target heat pump type and region. We determine whether the audit is mandatory for your target grant and what type of report is needed.
- Connecting you with an accredited auditor
We put you in touch with an SPW-certified auditor in your area. The visit lasts 1 to 2 hours and results in a PAE or PAE2 report compliant with the grant file requirements.
- Building the audit grant into the file
The audit grant is calculated and built into the overall assembly together with the heat pump Prime Habitation. We manage both files simultaneously to reduce your remaining cost as much as possible.
- Deducting the grants on the final bill
Audit grant + heat pump Prime Habitation + 6 % VAT: all grants are deducted directly from your bill. No cash advance, no waiting for reimbursement.
Looking for the grants available across all regions? Check our heat pump grants page or the specific heat pump grant Wallonia page for the amounts by heat pump type.
Estimate the net cost of your audit in 10 seconds
Select the type of audit you want to get a gross cost range. The audit grant is deducted depending on your income category.
Indicative estimate. The amount of the audit grant is confirmed after analysis of your file by the Public Service of Wallonia or the Brussels Region.
Home audit + air-to-water heat pump in Namur — net cost with grants
A concrete case illustrating the impact of the audit grant and the Prime Habitation Wallonia on the real remaining cost for a complete air-to-water heat pump installation.
Indicative example dated 2026. Amounts estimated for a middle-income household in Wallonia. Request your personalised quote for a costing tailored to your home and your income situation.
Everything you need to know about heat pump grants
- All heat pump prices in Belgium Comparison
Price ranges by heat pump technology, grants deducted: the full 2026 comparison.
See heat pump prices → - Heat pump grant Wallonia Regional grants
2026 amounts of the Prime Habitation Wallonia by heat pump type and income category.
Discover the Wallonia grants → - All heat pump grants Grants guide
Overview of national and regional grants to finance your heat pump in 2026.
Explore all grants →
Your questions on the home audit for a heat pump
Is the energy audit always mandatory to obtain a heat pump grant?
No, the audit is not systematically mandatory. In Wallonia, it is required to unlock the highest amounts of the Prime Habitation (cat. B and M). For a basic grant or in category E (high income), the audit is not required. We check your situation at the quote stage.
What is the difference between a home audit, a PAE2 and an EPC certificate?
The accredited home audit is an in-depth report carried out by an SPW-certified expert: it analyses the entire thermal envelope and the installations, and recommends a prioritised works plan. The PAE2 (Energy Audit Protocol version 2) is the standardised Walloon format of this report. The EPC certificate is simpler: it rates the building’s performance but does not recommend a detailed action plan. For heat pump grants, it is the accredited home audit (PAE2 format) that is accepted.
How much does an accredited home audit cost in 2026?
The cost of an accredited home audit ranges between 750 and 1 200 € depending on the floor area of the home and the auditor appointed. Before deducting the audit grant (up to 750 € for low incomes), the remaining cost can be nil or very low for eligible households.
What is the audit grant and can it be combined with the heat pump grant?
The audit grant is a specific grant that funds the cost of carrying out the energy audit. It is entirely separate from the heat pump Prime Habitation and can be combined with it. For low incomes, it covers up to 750 €; for middle incomes, up to 550 €. wendows builds both grants into the assembly of your file.
How long is the audit valid?
An accredited home audit is valid for 5 years from its date of issue. If a recent audit already exists for your home (for example carried out for another grant), it can be reused for the heat pump grant file without requiring a new visit.
Who can carry out the energy audit for the grant to be valid?
The audit must be carried out by an accredited auditor on the official list of the Public Service of Wallonia (SPW). A report produced by a non-certified firm will not be admissible when processing the grant file. wendows puts you in touch with certified auditors in your area.
Audit organised, grants deducted: we handle everything
We identify the audit requirement, coordinate the visit with an accredited auditor, calculate the audit grant and build the heat pump Prime Habitation file at the same time. Zero upfront, zero paperwork for you.
- Free check on the audit requirement
- Connection with an SPW-accredited auditor
- Audit grant + heat pump grant deducted from the bill