1) Who can benefit from the deduction?

The deduction targets investments assigned to a professional activity located in Wallonia. It applies to businesses, self‑employed and liberal professions, as well as certain non‑profit actors, when the investment is capitalised and linked to the activity carried out in Wallonia.

For private individuals in the strict sense (outside professional activities), the classic federal tax incentive does not apply in the same way. However, there are other grants and housing premiums that can supplement your renovation budget (insulation, heating, renewables, etc.).

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2) Eligible works and investments (overview)

The categories of investments are defined by the regulations (AR/CIR 92) and include in particular: limiting losses (insulation of existing buildings), insulation of pipes, reducing losses through ventilation (mechanical ventilation), recovery and supply of heat/cold, electrification of processes, temporary energy storage and production of renewable energy. Refer to the official lists for details by category.

Good to know: for existing buildings (or systems already in place), only certain categories may apply. Always check the exact category of your investment before committing.

3) Applicable rates: what changes from 2025

Since 1 January 2025, the reform of the investment deduction has introduced an increased thematic deduction for green investments:

• 40 % for SMEs and the self‑employed

• 30 % for large companies.

For earlier investments (e.g. 2024), different rates applied. Check your tax year and the exact period of expenses to identify the right regime before filling in your return.

4) Steps: how to obtain the attestation

Step 1 — Gather your documents

Prepare the invoices, a detailed list and, if necessary, a technical calculation note justifying the energy savings. These items will be used to assess your application.

Step 2 — Submit the request within the time limits

The request for an attestation must be submitted after the works have been carried out, and no later than 3 months after the end of the fiscal year during which the investment was made. After this period, the request is not processed.

Step 3 — Where and how to file?

Submit your file via My Space (Wallonia’s platform) by filling in the online form. According to the procedure described by Wallonia, make sure to complete one form per tax year and per group of products/technologies concerned.

Step 4 — Use the attestation for your tax return

Once the attestation has been issued, you attach it to your tax return (specific tax forms, e.g. 276U/277U as the case may be). Refer to the SPF Finance instructions for the exact procedures.

ℹ️ For multi‑year projects, an eligibility certificate can be requested beforehand, but it does not replace the annual attestation per fiscal year.

5) Practical tips for individuals

• Have eligibility confirmed before signing: ask the company to indicate the regulatory category targeted.
• Keep all evidence (quotes, technical data sheets, detailed invoices, commissioning certificates).
• Plan ahead to meet the 3‑month deadline after year‑end.
• Combine with housing grants if you are not in a professional context (insulation, boilers, renewables…).

To obtain reliable and comparable quotes, work with verified local companies and state your priorities clearly (comfort, savings, budget, schedule). You can easily find them on RenovSmart.com.

FAQ — Frequently asked questions

Does the deduction apply to all works in a private home?

No. The investment deduction applies to assets linked to a professional activity located in Wallonia. For a private home, find out about housing grants and appropriate regional aids.

What are the rates in 2025?

Increased thematic deduction: 40 % for self‑employed/SMEs, 30 % for large companies (green investments). Check the conditions and the correct category before declaring.

What happens if I miss the deadline?

Requests submitted more than 3 months after the end of the fiscal year are not processed. Plan your timetable from the time you sign the work contract.

Take action

Official sources and useful resources

• SPW Energy — “Tax deduction for energy‑saving investments”. View the page.
• Public Service of Wallonia — Procedures (attestation via My Space). Procedure and deadlines.
• Wallonia — “Benefit from a tax deduction…”. See the factsheet.
• Federal Public Service Finance — “Investment deduction” (general framework and forms). Official information • Form 276U (PDF).
• SPW Energy — Appendices (lists of investments and technical details). Annex I (PDF).
• Housing grants and premiums — Wallonia Energy Portal (for households). See aids.