Frequently asked questions about asbestos diagnosis in Western Switzerland
When is asbestos diagnosis mandatory in Switzerland?
Asbestos diagnosis becomes mandatory as soon as a construction or demolition project is planned on a building constructed or significantly renovated before 1 March 1990. This obligation derives from the Ordinance on Construction Work (OTConst, RS 832.311.141), which requires the employer — and by extension the project owner — to verify the absence of hazardous substances, including asbestos, before any construction site likely to disturb old materials.
The obligation applies regardless of the scale of the works: a simple drilling operation, window replacement, tile removal, or complete building rehabilitation are all covered. There is no minimum works threshold below which the obligation would not apply.
For total or partial demolition, the obligation is even more extensive: the inventory must cover the entire building or the part to be demolished, not only the directly impacted zones.
Outside of any construction project, diagnosis is not mandatory under Swiss law — but it is strongly recommended before a property purchase and useful for the preventive management of a building portfolio.
Is an asbestos diagnosis needed to redo a bathroom in a 1975 apartment?
Yes, without exception. An apartment built in 1975 is clearly within the scope of the pre-works diagnostic obligation. The bathroom of an apartment from this period may contain several types of asbestos-containing materials: adhesive under wall or floor tiles, 30x30 cm vinyl floor tiles with their adhesive underlay, smoothing renders, mastic seals around the bathtub or shower tray, and potentially fibre cement sheets behind the tiling.
When removing tiles, sanding renders or pulling up floor tiles, these materials can release asbestos fibres if the tradesperson does not have appropriate equipment and if protective measures are not put in place. The tradesperson themselves, as an employer, has the obligation to ensure the absence of asbestos before intervening.
In practice, most professional tilers and tradespeople refuse to work in pre-1991 bathrooms without a prior asbestos diagnostic report — and they are right to do so.
Is a diagnosis needed before replacing kitchen or entrance tiling?
Yes, for the same reason as for the bathroom. Adhesives used for tile laying in buildings constructed before 1990 frequently contained asbestos. It is not possible to visually distinguish asbestos-containing adhesive from non-asbestos-containing adhesive — only laboratory analysis makes this possible. Mechanical tile removal (grinding, chiselling, cutting) releases dust that can contain fibres if the adhesive is asbestos-containing.
The diagnosis must cover the tile zone to be replaced as well as adjacent surfaces likely to be disturbed.
Is an asbestos diagnosis necessary for window replacement?
Yes, in most cases for buildings predating 1991. Mastic seals around old window frames may contain asbestos. These seals, often applied at the interface between the frame and the masonry or between the frame and the window reveals, can release fibres when old frames are removed.
Furthermore, certain materials in window sills or interior window ledges may also be affected. Window removal in an old building must therefore be subject to prior verification.
What to do if the diagnosis reveals the presence of asbestos?
The discovery of asbestos in a building does not necessarily mean a halt to all projects or an emergency situation. The course of action depends on the recommendations formulated in the report:
If the recommendation is “removal before works”: asbestos-containing materials identified in the works zone must be removed by a decontamination specialist before ordinary works begin. Once decontamination is complete, works can resume normally. Decontamination itself gives rise to a special waste tracking document.
If the recommendation is “monitoring”: the material is in good condition and will not be disturbed during the works. It can remain in place, but must be indicated to companies working on the site so that they take necessary precautions if their works approach it.
If the recommendation is “no action required”: the material is stable and outside the works scope. Its presence is documented for information.
In all cases, the diagnostic report is the reference document that guides decisions. Decontamination companies prepare their offers based on the information contained in this report.
Who can carry out an asbestos diagnosis in Switzerland?
In Switzerland, asbestos diagnosis must be carried out by a specialist recognised by the FACH Commission (Fachkommission Asbest und andere Schadstoffe im Hochbau). This commission issues professional recognitions at three levels (level 1, 2 and 3) corresponding to increasing degrees of competence.
For a standard asbestos diagnosis before works or before demolition, level 1 is the minimum required. The diagnostician must also work with a laboratory accredited by the Swiss Accreditation Service (SAS) for sample analyses.
A report produced by a person without FACH recognition may be refused by cantonal authorities when applying for a building permit. It does not offer the same guarantees in terms of professional liability. For more information on qualification criteria, see our asbestos diagnostician Western Switzerland page.
How long does it take to receive the results of a diagnosis?
The complete process takes place in two stages:
The on-site visit is scheduled according to the diagnostician’s and the property’s availability. It generally lasts from a few hours for an apartment to a full day for a villa or apartment building. For industrial buildings or large complexes, several days may be necessary.
Laboratory analyses take 5 to 10 working days under standard turnaround times. Accelerated processing options (2 to 3 days) are available in emergencies, at a surcharge.
The final report is submitted once the analysis results are available, generally within the days following their receipt by the diagnostician.
In summary: for a standard diagnosis on an apartment or villa, allow approximately 2 to 3 weeks between ordering and receiving the final report. For urgent projects, accelerated solutions can reduce this deadline to approximately one week.
Is asbestos diagnosis mandatory before a property purchase in Switzerland?
No. In Switzerland, unlike in some neighbouring countries, no law imposes an asbestos diagnosis prior to the sale of a property. There is no Swiss equivalent of the French “dossier de diagnostic technique”.
However, the Code of Obligations (CO, art. 197-199) requires the seller to declare the hidden defects of the property of which they are aware. The presence of asbestos in poor condition, likely to generate significant decontamination costs, may constitute a hidden defect if the seller was aware of it and did not declare it. Warranty of defects recourse is possible within one year of discovering the defect, two years after transfer of ownership for real estate.
In practice:
- For a buyer: requesting a diagnosis before signing the final contract is a useful precaution that allows negotiation with full knowledge of the situation
- For a seller: having a report allows the buyer to be informed in good faith and guards against subsequent recourse
What is the difference between a pre-works and a pre-demolition diagnosis?
The fundamental difference is the scope of investigation:
Before works: the diagnosis is targeted at the zones and materials likely to be disturbed by the planned interventions. If you are only redoing the bathroom, the diagnosis covers the materials of that room and its immediate surroundings. It is a targeted inspection, proportionate to the project.
Before demolition: the inventory must cover the entire building or the part to be demolished. There are no excluded zones, as during demolition all materials will be disturbed. The inventory is exhaustive and includes the quantification of volumes of asbestos-containing materials to plan their disposal through regulatory channels.
Another important difference is the objective: the pre-works diagnosis primarily aims to protect workers during the construction site, while the pre-demolition inventory aims both at worker protection and correct management of asbestos waste according to the Ordinance on the Movement of Waste (OMoD).
Our asbestos diagnosis before demolition page details these specifics.
What exactly does an asbestos diagnostic report contain?
A complete asbestos diagnostic report includes the following elements:
- Identification information for the property, the commissioning party and the diagnostician (with their FACH recognition number)
- Description of the mission and the inspection scope
- Methodology employed and inspection conditions
- Detailed inventory of inspected materials, zone by zone and room by room, with their location, nature, state of conservation and sample reference
- Results of the SAS-accredited laboratory analysis for each sample taken
- Risk assessment for each identified asbestos-containing material
- Action recommendations (priority removal, scheduled removal, monitoring, no action)
- Photographic documentation of inspected zones and materials
- Original laboratory analysis results in the appendix
Our asbestos diagnostic report page explains the structure and use of the report in detail.
What is the validity period of an asbestos diagnostic report?
The validity period of a report is not uniformly regulated at the federal level. In the canton of Vaud, practice retains a validity period of 3 years, provided no significant modification of the building has occurred since the inspection.
In other Western Swiss cantons, a similar period of 3 years is often retained as a practical reference, but cantonal practices may vary.
A report must be updated in the following situations:
- Works have been carried out in the inspected zones since the report was drafted
- Significant deterioration has been observed on identified asbestos-containing materials
- The report is more than 3 years old and new works are planned
- The conditions of use or occupation of the building have changed significantly
- A disaster (fire, flood) may have affected the condition of the materials
Is asbestos present in vinyl floor tiles?
Yes, frequently. 30x30 cm vinyl floor tiles (sometimes 20x20 cm) manufactured and laid between the 1950s and 1980s are one of the most common sources of asbestos in buildings of that period. These tiles, known as “vinyl-asbestos”, typically contain chrysotile asbestos in their composition, with concentrations reaching 20 to 30% of the material’s weight.
The risk is not linked to the presence of the tiles themselves, as long as they are intact and undisturbed. It manifests when they are removed, cut or sanded, which releases fibres.
Furthermore, the adhesive used to fix these tiles to the substrate may itself contain asbestos or PAHs (in the case of bituminous adhesives). A double verification — tiles and adhesive — is necessary.
Can asbestos be found in tile adhesive?
Yes. Adhesives used for tile laying in bathrooms, kitchens and other rooms in buildings constructed before 1990 frequently contained chrysotile asbestos as a filler or reinforcement. These adhesives are generally grey or beige in colour and have the appearance of hardened mortar. They are present under the tiles, sometimes covering the entire tiling surface, sometimes in dabs at the corners and centre of each tile (dot-and-dab method).
The asbestos content of these adhesives varies according to the products and manufacturers. Some products have very low concentrations, others significant concentrations. Only laboratory analysis can determine whether a specific adhesive contains asbestos and in what proportion.
This material is particularly relevant for diagnosis before renovation of a bathroom or kitchen, and before any tile replacement in an old building.
Do common areas of a condominium (PPE) need to be diagnosed?
Yes. The common areas of a condominium (PPE) — corridors, stairwells, cellars, technical rooms, roof, facade — are subject to the same obligations as any collective building. If works are planned in these common areas, a prior diagnosis is mandatory.
The responsibility falls on the PPE management (condominium association or assembly of co-owners, represented by its administrator). The PPE administrator has a duty of diligence towards co-owners and occupants: they must ensure that works carried out in common areas comply with legal obligations, including asbestos diagnosis.
In practice, serious property managers and administrators systematically integrate asbestos diagnosis into their preparation procedures for works on buildings predating 1991.
How to choose a good asbestos diagnostician in Switzerland?
The primary criterion is FACH recognition: verify that the diagnostician holds a currently valid recognition issued by the FACH Commission. This recognition guarantees certified training, up-to-date regulatory knowledge and the use of SAS-accredited laboratories.
Additional points to verify:
- The FACH recognition level (level 1 minimum for a standard diagnosis)
- The SAS-accredited laboratory with which the diagnostician works
- Professional civil liability insurance coverage
- Ability to operate in your canton and geographical zone
- Intervention and report delivery deadlines
- Clarity and completeness of produced reports (ask for an anonymised example if possible)
Be wary of offers with very short turnaround times (inspection and report within 24h without analytical delay) or abnormally low prices that could indicate an insufficient number of samples or non-compliant analyses. A serious asbestos diagnosis takes the time it needs.
To choose a diagnostician in Western Switzerland, visit our asbestos diagnostician Western Switzerland page or request directly a no-obligation quote.
Is it possible to stay in a residence during the diagnosis?
Yes, as a general rule. The inspection visit and samples taken by the diagnostician do not require prior evacuation of occupants. Samples are taken according to protocols that minimise fibre release, and the diagnostician has appropriate personal protective equipment.
It may be recommended that occupants — particularly children and pregnant women — temporarily move away from the room in which a sample is being taken. But it is not necessary to leave the residence for the duration of the visit.
The situation is different if the diagnosis reveals the presence of heavily degraded or friable materials that are releasing fibres into the ambient air: in this case, a dust measurement and possibly a decontamination intervention may prove necessary before maintaining normal occupation.
How much does an asbestos diagnosis cost?
The cost of an asbestos diagnosis depends on several factors: the surface area of the property, the number of materials to sample, the complexity of access and the urgency of the intervention. For a standard apartment, count a few hundred francs. For a villa or apartment building, the cost will be proportional to the surface area and the number of samples required. The most reliable approach is to request a personalised quote — it is free and without obligation.