In the 1970s, Belgium was the world's leading consumer of asbestos per capita. The consequences are still felt today: an estimated three to four million tonnes of asbestos remain in Flemish buildings. A general asbestos ban has applied since 2002, but material incorporated before that date remains in place — in roofs, façades, floor coverings, insulation, pipework and plasterwork. That is precisely why asbestos is not a historical file but a daily legal reality in every purchase, sale, letting or renovation of an older property.
Anyone transferring or renovating a property soon runs into a tangle of obligations and liabilities: the Flemish rules on the asbestos certificate (officially the asbestos inventory certificate, Dutch "asbestattest"), the pre-contractual duty to inform a buyer or tenant, the classic warranty for hidden defects, the liability of the contractor who encounters asbestos, and even neighbour nuisance and tax consequences. This guide pieces that puzzle together and refers, for each topic, to an in-depth article.
What is asbestos and when does it become a legal problem?
Asbestos is a collective name for a series of fibrous silicates used for decades for their fire-resistant, insulating and cheap properties. Legally, the distinction between bonded and non-bonded asbestos matters most. VLAREM II defines those concepts in article 1.1.2: in bonded applications — asbestos cement, corrugated sheets, floor tiles, pipes — the fibre is fixed in a carrier material and is barely released in normal use. Non-bonded asbestos, such as sprayed asbestos or certain pipe insulation, is far more dangerous because the fibres can come loose and spread through the air.
That distinction explains why asbestos does not automatically amount to a legal defect. The condition of the material and the intended use of the property are decisive. Bonded asbestos in good condition in a house sold "for renovation" is quite different from damaged asbestos in a property presented as "ready to move in". The construction-year threshold of "2000 or earlier" is no coincidence: a general asbestos ban has applied since 1 January 2002, so buildings from before 2001 are precisely those in which asbestos could still lawfully be used.
The asbestos certificate: when is it compulsory and what does it contain?
The most concrete obligation is the asbestos inventory certificate, introduced by the Materials Decree of 29 March 2019. Since 23 November 2022 the owner must communicate the content of a valid asbestos certificate to the prospective buyer on concluding the private sale agreement (compromis), whenever an "accessible structure with a risk construction year" is involved (article 33/14 of the Materials Decree). In concrete terms: a building built in 2000 or earlier with an accessible surface of at least 20 m².
The phased roll-out until 2032
The obligation will be extended step by step in the coming years. For the common parts of apartment buildings, the deadline is 1 January 2027. Landlords of older properties must hold a certificate by 2030 and, if they have one, give the tenant a copy (article 33/9 §2). And under article 33/9 §1, every owner of a building from before 2001 must have an asbestos certificate by 2032 — under the decree by 31 December 2031 at the latest — regardless of any sale.
A certificate is as a rule valid for ten years, but only five years where high-risk material is present. Since 8 April 2024 a certificate finding "no asbestos" is valid indefinitely. What the certificate covers, who draws it up and when you need it is explained in our article on what an asbestos certificate is.
The certificate does not release the seller
What is often underestimated is that the certificate does not shield the seller. It is drawn up by a certified asbestos inventory expert (article 33/16), on the basis of a non-destructive inspection, and registered in the database of the Flemish waste agency (OVAM). It is, in other words, an obligation of means, not an absolute guarantee. "Asbestos-safe" does not mean "asbestos-free". The owner moreover retains his own, reinforced duty to inform: article 33/10 obliges him to declare on his honour any enclosed or covered asbestos of which he knows or ought to know — precisely the asbestos the expert cannot see in a non-destructive inspection.
The nullity sanction is strict
The sanction for non-compliance is severe. If the sale is concluded without valid communication, the buyer may claim the nullity of the transfer under article 33/14 §6. That nullity is relative — only the buyer can invoke it — and can only be validly remedied if the buyer has received a valid certificate and expressly waives the nullity claim in the notarial deed. A standard clause stating that "the buyer waives all nullities" is therefore not enough.
This regime is deliberately modelled on that of the soil certificate, on which the Court of Cassation ruled on 25 March 2011, the Antwerp Court of Appeal confirming on 15 June 2015 that the sale agreement is a solemn contract whose formal requirements must be strictly observed. For the notary this means actively verifying that the certificate was communicated in time and in full; a routine clause offers no cover.
Asbestos and hidden defects on sale
The asbestos certificate stands alongside, not in place of, the classic warranty for hidden defects (art. 1641 et seq. of the old Belgian Civil Code). A buyer who discovers asbestos after purchase can rely on it where the defect was hidden, is sufficiently serious and already existed at the time of the sale.
The crucial words are "sufficiently serious". The case law does not accept that the mere presence of asbestos suffices. The Court of Cassation held on 9 May 2016 that impairment of the economic value alone is insufficient: there must be a substantial reduction in use. Thus asbestos in the subsoil of land sold, entailing a remediation obligation and restrictions on use, was recognised as a hidden defect even without any standard being exceeded (Commercial Court of Dendermonde 12 September 2013). Conversely, the Commercial Court of Brussels held on 23 March 2015 that asbestos in a building 35 to 45 years old does not automatically constitute a serious defect. Bonded asbestos in good condition therefore usually falls short of the threshold.
Hidden and in time
The defect must also genuinely be hidden. Under settled cassation case law (including Cass. 29 March 1976 and Cass. 6 December 2001), a defect is hidden when it is not visible on a normally attentive examination immediately after delivery. Asbestos that was visible, or apparent from documents provided, does not qualify.
Equally important is the short period of article 1648 of the old Belgian Civil Code: the buyer must act "within a short time" after discovery. That period is a forfeiture period, not a limitation period (Cass. 29 November 2013), which aggravates the consequences. Serious negotiations may suspend it, but an ordinary e-mail does not suffice (Mons 5 June 2014). Interestingly, the short period does not apply where the seller expressly guaranteed the absence of asbestos (Court of Walloon Brabant 3 June 2015) — a pitfall we return to below. Choose the correct legal basis in advance, too: a buyer who invokes the warranty for hidden defects cannot later fall back on the delivery claim (Cass. 19 October 2007). How that assessment works and which remedies the buyer can seek is discussed in our article on asbestos as a hidden defect.
Looking ahead: Book 7 of the Civil Code
Important legislation is on its way. The new Book 7 of the Belgian Civil Code will replace the distinction between visible and hidden defects with a single broad conformity obligation (article 7.2.30): the seller must deliver a good that corresponds to what was agreed. At the time of publication Book 7 is not yet in force, but anyone buying or selling today should monitor its entry into force, as it may thoroughly redraw the assessment of asbestos disputes.
The duty to inform of seller, estate agent and notary
Even before hidden defects come into play, there is the pre-contractual duty to inform. Article 5.16 of the Belgian Civil Code requires parties to give each other, during negotiations, the information that statute, good faith and common practice demand. Anyone who deliberately conceals a known asbestos problem risks not only liability but even fraud (article 5.35): intentionally withholding essential information may amount to an artifice rendering the sale voidable. Fraud is not presumed and must be proven, but unlike with hidden defects no "sufficiently serious" defect is required — the deception itself suffices.
Other information carriers also belong here. The post-intervention file (PID), compulsory for works carried out after 1 May 2001, documents which materials and interventions were used in the building. The soil certificate may reveal contamination or completed remediation and is itself compulsory on pain of nullity. An incomplete or "to be provided later" PID is a classic pitfall: hand it over with the compromis, not afterwards, because the later delivery often never happens and can be construed as an artifice. The roles of seller, estate agent and notary are covered in our article on the duty to inform on asbestos.
Exoneration and guarantee clauses: what works and what does not
Sellers often try to exclude their liability with a non-warranty clause, such as the clause that a property is sold in the state in which it is found. Such clauses are in principle valid — the Brussels Court of Appeal confirmed this again on 5 February 2021, finding that a lay seller is not obliged to search for asbestos himself — but they run up against clear limits.
The first limit is bad faith. A seller who knew of the defect cannot rely on his exoneration clause (article 1643 of the old Belgian Civil Code); if he knew of it, he is even liable for all damage, including consequential damage, because the law presumes he knows all its consequences (article 1645). The second limit is the seller's capacity. A professional seller is presumed to know the defect; the distinguishing criterion is his degree of specialisation and technical competence (Cass. 7 April 2017). Towards a consumer, an exoneration for hidden defects is moreover void where the seller is an undertaking (Mons 8 January 2019). And a "self-builder" who built or converted on his own account does not escape either: he is deemed to know the defects of his own work (Cass. 18 February 2019).
Beware of the opposite move: the converse is at least as dangerous. Estate agents sometimes have sellers sign a clause "guaranteeing the absence of asbestos". With an older house that is asking for trouble: asbestos is almost always present, and such an express guarantee precisely disables the protective short period. A nuanced wording ("to the seller's knowledge, no asbestos has been found except ...") is safer. A clause must, incidentally, genuinely aim at exoneration: a declaration that "to the seller's knowledge there are no hidden defects such as asbestos or dry rot" is a mere confirmation, not an exoneration clause (Commercial Court of Brussels 12 December 2003). The dos and don'ts of such clauses are set out in our article on exoneration and guarantee clauses on asbestos.
Asbestos in lettings
Asbestos also matters outside sales. A landlord must offer a dwelling meeting the elementary requirements of safety, health and habitability (article 2 of the former Residential Lease Act, today the Flemish Housing Code). Released asbestos fibres strike directly at those requirements. The Justice of the Peace of Ghent held on 8 February 2016 that released asbestos constitutes a serious and structural defect justifying termination of the lease at the landlord's expense (article 1184, second paragraph, and article 1741 of the old Belgian Civil Code).
On top of that comes the certificate obligation: a landlord who holds a valid asbestos certificate must give the tenant a copy — when the lease is entered into, or within one month if the certificate is issued during a current lease (article 33/9 §2). Comparable consequences apply in agricultural tenancy: asbestos in farm buildings or stables can affect the tenancy compensation (Justice of the Peace of Zomergem 27 April 2012). What this means in practice for landlords is set out in the asbestos certificate for rentals.
Asbestos in renovation and demolition: the contractor
As soon as works start, the focus shifts to the contractor. His liability is twofold: environmental-criminal and contractual.
Environmental criminal law and safe removal
Removing asbestos is strictly regulated. VLAREM II (article 4.7.0.1) determines how asbestos must be managed: certain self-removable applications may be taken away under conditions (§2), but the material must be wetted, no high-pressure or sanding machines may be used, a P3 dust mask must be worn and no minors may be involved (§3); certain tools are prohibited altogether (§5). Anyone who ignores these rules and spreads fibres risks criminal prosecution, and both the company and the natural person involved can be convicted (Criminal Court of Ghent 22 April 2008). A contractor was thus convicted for failing to apply the required hermetic zone when removing a vinyl floor (Criminal Court of East Flanders, Ghent division, 21 January 2020).
Demolition brings additional obligations. Besides the asbestos inventory, a demolition follow-up plan is required for larger volumes (VLAREMA, article 4.3.3): infrastructure works from 250 m³, residential buildings from 5,000 m³ and non-residential buildings from 1,000 m³. The principal or demolition contractor can have the follow-up supervised by a recognised demolition management organisation — in Flanders today Tracimat — which brings legal certainty as well as a reduced landfill and processing rate. Importantly, the employer's asbestos inventory obligation, anchored in the Code on Well-being at Work (Book VI, Title 3), continues to apply even where an external contractor is engaged (Cass. 25 November 2019).
Who bears the risk of "unforeseen" asbestos?
Contractually, the question is whether asbestos is an unforeseeable circumstance justifying a price revision (articles 1147-1148 of the old Belgian Civil Code on external cause). The answer depends on what the contractor knew or could have known. A contractor who knew of asbestos — for instance because a prior report recommended further investigation — and still quoted a fixed price assumes that risk and cannot later plead unforeseeability (Liège 19 March 2019). A professional contractor is not simply equated with a professional seller (Cass. 5 December 2002), although a presumption of knowledge may also rest on him unless the defect was undetectable (Liège 11 June 2007).
A special figure is the qualitative action: a principal who received asbestos-contaminated material — think of the case of blasting grit contaminated with asbestos — can act directly against the supplier or producer (articles 1615 and 1641 of the old Belgian Civil Code; Cass. 18 May 2006). Principals and contractors alike would do well to address asbestos expressly in the contract. We develop this in the contractor's liability in demolition.
Asbestos in co-ownership and the role of the syndic
In an apartment building the first question is one of classification: is the asbestos private or common? Asbestos in the individual unit is in principle a matter for the co-owner concerned, but it often sits precisely in the common parts — roofs, façades, service shafts, technical rooms. Where the classification is unclear and the asbestos serves all co-owners, it is generally deemed a common part, with the co-owners' association (VME) as the responsible party (by analogy with French Cass. 7 May 2003, with due reservation as to transposability).
The syndic (building manager) is the pivotal figure. A professional syndic is expected at least to suspect asbestos in a building from the 1960s or 1970s and to put the subject on the agenda of the general meeting before works are carried out. The liability of the co-owners' association and that of the syndic must be distinguished: the Brussels Court of Appeal held on 20 October 2017 that a co-owners' association is not a "habitual workplace", which affects attribution. The certificate obligation for the common parts, with its deadline of 1 January 2027, also falls within the syndic's management duties. How liability is apportioned is discussed in asbestos in apartment co-ownership.
Asbestos, the neighbours and DIY removal
Asbestos does not respect plot boundaries. When fibres end up on someone else's property — after a fire, damage or improper roof cleaning — the doctrine of neighbour nuisance comes into play (the balance doctrine, historically based on article 544 of the old Civil Code and today enshrined in Book 3 of the Belgian Civil Code, art. 3.101). The presence of corrugated asbestos sheets is not in itself a fault, but whoever installs, has installed or keeps them can be liable for the excessive nuisance caused by released fibres, even without proven fault — although a purely theoretical risk does not suffice. Read more in asbestos and neighbour nuisance.
DIY removal of asbestos is also strictly regulated. A private individual may remove certain bonded, undamaged applications himself under strict conditions — wetting, no breaking, no high-pressure or sanding machines, proper protection and correct disposal. High-risk and non-bonded asbestos must be removed by a licensed firm. The Materials Decree moreover expressly prohibits cleaning or de-mossing an asbestos roof or façade.
Practical conclusion
Asbestos touches virtually every link in a real estate transaction: the seller with his information and certificate duties, the buyer with his hidden defects claim, the landlord with his habitability duty, the contractor with his environmental and contractual responsibility, the co-owner and syndic with their management duties, and even the neighbour who gets fibres over the hedge. The asbestos certificate is an important but limited first step: it informs, but it releases no one from liability.
How Reius Lawyers can assist you
Do you have a concrete file in which asbestos plays a role, as buyer, seller, landlord, contractor or co-owner? Reius Lawyers assesses your rights and obligations, reviews your certificate, clauses and contract, and assists you in proceedings where needed. Feel free to contact us at info@reius.be or via the contact form.
In re. In iure — Thorough on the facts. Considered in law.