Illustration generated for this guide. It does not represent a property for sale.
Original ComparImmo illustration created for this guide.
The soil certificate belongs in the sale file
You view a house in Flanders and find a bodemattest, the soil certificate, among the documents. A short sentence in that certificate may sound reassuring. Before using it in your decision, check exactly which land it covers and what the statement means. OVAM explains that the certificate contains the relevant information it knows about the land. It is required before concluding an agreement to transfer land, whether classified as risk land or non-risk land. This guide concerns the Flemish system. It does not apply that procedure to Brussels or Wallonia. The document answers a different question from the building’s asbestos certificate. Keep their purposes separate in your file. A favourable entry in one does not supply missing information in the other. Request the complete document with any annexes rather than relying on the seller’s verbal assessment.
Make sure the references cover your purchase
The certificate includes cadastral details and information from OVAM’s register. Start with the references: division, section and parcel number. Compare them with the documents describing the sale. Do not rely only on the postal address, particularly where the purchase includes a separate garden, an outbuilding or several plots. To read a property file, make a short record linking each parcel to an identified document. Note the certificate date and the references of any reports listed. Request a plan or annex if it is mentioned but missing. Keep a question open where two documents use different references. The notary can clarify their relationship and the scope of the transaction. This documentary check helps avoid comparing a complete house with information covering only part of what you intend to buy.
When no information is available
In its interpretation guidance, OVAM explains that a certificate sometimes described as « blank » can reflect the absence of relevant information in its register. It does not establish that the land is free from contamination. Keep the distinction clear: missing knowledge is not a favourable test result. You do not need to turn that absence into an automatic suspicion. Ask which documents exist about previous use of the land and whether its soil status has been checked for the sale. A specific question is more useful than a general judgement: « Is this conclusion based on a study, or on the absence of recorded information? » Where a study is included in the file, request its complete version. Garden photographs, careful maintenance or an attractive interior renovation do not answer that question.
Risk land requires its own check
For risk land, the obligations described by OVAM include a certificate and a valid exploratory soil investigation, subject to applicable exemptions. Depending on the findings and necessary measures, additional transfer conditions may apply. The presence of a certificate alone therefore does not establish that every step has been completed. Before preparing your purchase offer, ask the notary which documents and decisions are needed in your case. Have technical questions explained by a recognised soil remediation expert. Separate what is known, what still needs doing and the implications for your timetable. Ask who will provide the next answer and which document will support it. A date on which you commit to the purchase needs a firmer basis than a verbal assurance.
Compare files without inventing costs
Fictional example: for one house, you have read a certificate and a complete investigation report. For a second, the seller supplies only the certificate’s first page. Those files do not provide the same level of information. That is not enough to declare the first house risk-free or the second contaminated. To compare several properties, use separate rows: identified parcels, complete certificate, available investigations, open technical questions and the notary’s response. An entry marked « to request » makes the table more reliable than an overall score without supporting evidence. Reconsider the asking price when the answers become available. If you intend to undertake works, keep the renovation budget separate. Do not insert a standard remediation allowance into your calculation without technical advice and an appropriate cost basis for the file. A financial reserve can be a working assumption. It establishes neither the actual expense nor how obligations are allocated between the parties.
Use the summary to prepare focused requests
In ComparImmo, a PDF with readable text can help prepare a summary. Use that summary to note the parcels named, reports mentioned and documents still missing. Check the answers against the original document. A summary does not physically investigate soil, approve a transfer or replace explanations from OVAM, the notary or the expert. After buying, keep references and original documents within a consistent filing structure. Proprioo’s guide to organising a rental file recommends distinguishing signed versions from drafts and retaining the property’s history when the tenant changes. That advice complements the follow-up of your purchase documents; it does not provide a soil diagnosis. Before making a commitment, request written answers to outstanding questions. You should be able to retrieve the document supporting each conclusion and know who will handle the remaining checks.
Sources and references
ComparImmo editorial team. Sources checked on 5 October 2026. Check the rules for the region and your circumstances before making a commitment.