Illustration generated for this guide. It does not represent a property for sale.
Ask for the complete certificate
You have seen a letter in the listing. Now request the certificate, check its address and look at its date. Terminology and rules depend on the region: PEB in Wallonia and Brussels, EPC in Flanders. Consult the authority responsible for the property’s region rather than a summary applying elsewhere.
Look at the home’s equipment
Read the information about insulation, windows, heating and ventilation. Compare it with what you see during the viewing. If recent work is advertised, request supporting documents and ask whether it is reflected in the certificate. A letter alone describes neither your future comfort nor all the work to consider.
Prepare your next step: A house to renovate: move beyond guesswork in your budget
Turn your reading into practical questions
Which improvements would suit your plans? In what order? Which items should be assessed together? Request an assessment suited to the building before setting a budget. For requirements and deadlines applying to your purchase, check the regional rules in force when you make your decision.
Look beyond the displayed rating
An energy certificate describes performance according to a calculation method. It is not your future personal energy bill. Consumption also depends on how you use the home, the number of occupants and your habits. Read the characteristics used and the recommendations, then ask about anything surprising. Differences between two properties need context. Certificate names, rules and procedures vary by region: always start with the document for the address concerned.
Compare the certificate with what you see
During the viewing, note accessible equipment and work for which the seller can provide evidence. If recent insulation is mentioned, ask where it was installed and which documents support that statement. If changes were made after the certificate, have the situation clarified before comparing figures. You do not need to repeat the certifier’s work. Your aim is to understand any gap between the certificate, listing and explanations received, then put your questions to someone qualified.
Establish a sensible order for work
Before choosing a heating appliance, have the whole home and its needs assessed. Insulation, ventilation and heating should be considered together with the relevant professionals. Request several proposals specifying included items, constraints and timing. Include financial assistance in your funding only after checking the current conditions applying to your project. Keep a budget version that works without it while approval remains uncertain. The certificate’s recommendations then become a starting point for questions and quotations.
Sources and references
ComparImmo editorial team. Sources checked on 27 September 2026. Check the rules for the region and your circumstances before making a commitment.