Asbestos Diagnosis Before Work

Pre-works diagnosis: the most common situation in Western Switzerland

Among all situations where an asbestos diagnosis is required, the pre-works diagnosis is by far the most frequent. In the cantons of Geneva and Vaud, a significant proportion of the building stock was constructed or renovated between the 1950s and the late 1980s — during the period of intensive industrial use of asbestos. Every renovation project, whether involving a villa in the Lausanne suburbs, a Geneva apartment from the 1970s or a commercial building from the 1960s, is potentially concerned.

In Switzerland, the obligation to carry out an asbestos diagnosis before works is not a best-practice recommendation: it is a binding legal requirement, accompanied by criminal and civil sanctions for non-compliance. Failure to conduct a prior diagnosis exposes the client, the construction company and the architect to serious consequences — well beyond the operational extra costs of discovering asbestos during construction.

Good to know: The obligation to carry out an asbestos diagnosis before works applies regardless of the scale of the site. A simple tile replacement, fitting an electrical outlet in an old partition wall or replacing a window in a 1975 building triggers the same legal obligation as the complete rehabilitation of a building.

The legal obligation: what the OTConst requires

The reference text

The Ordinance on Construction Work (OTConst, RS 832.311.141) is the central text. Its articles 3 and 46 and their implementing provisions require the employer — including the client commissioning the work — to verify before any construction site commences the presence of hazardous substances in the zones affected by the work.

This obligation covers:

• All buildings constructed or significantly renovated before 1 March 1990
• All categories of work, regardless of scale
• All types of clients: private owners, developers, property managers, public authorities, tenant companies

The client’s responsibility

The term “employer” in the sense of the OTConst does not refer solely to a company. A private property owner who commissions a renovation company or even a single tradesperson for work at their home is considered a commissioning party and bears part of the responsibility for working conditions on their site.

Important: A private property owner having their bathroom renovated is subject to the same legal diagnostic obligation as a property developer rehabilitating an entire building. Ignorance of this rule is not an acceptable argument in the event of an inspection or accident on the site.

The company’s responsibility

The construction company is itself an employer and cannot fully shift responsibility to the client. A serious professional contractor systematically requires the asbestos diagnostic report before starting work and refuses to proceed without this document.

The architect’s responsibility

The commissioned architect has an advisory obligation. They must integrate the asbestos issue from the study phase, alert the client and organise the diagnosis within the project timeline before any tendering of companies.

All types of work requiring a diagnosis

Complete table by category

Interior renovation in detail

Interior renovation is the most common context in the Geneva and Vaud residential stock. The most frequently encountered risk materials are:

• Tile adhesives: applied in bathrooms and kitchens before 1990, they may contain chrysotile. Their removal — mandatory when replacing tiles — releases fibres if not handled by an authorised company.
• 30×30 cm vinyl floor tiles: used massively in the 1960s–1980s, they frequently contain asbestos and their laying adhesive is almost systematically asbestos-containing.
• Interior renders: certain sprayed renders applied before 1990 incorporate asbestos. Sanding or patching them releases fibres in a confined space.
• Lightweight fibre cement partitions: these constitute a non-friable material that becomes dangerous as soon as it is drilled, cut or demolished.

External works and roofing

Corrugated fibre cement sheet roofing is the most visible and widespread asbestos application in Western Switzerland. Single-family homes built between 1950 and 1985 in the Geneva and Vaud countryside are very often equipped with them, as are outbuildings, garages, garden shelters and agricultural buildings.

These sheets, when in good condition, do not spontaneously release fibres. But their replacement — even by experienced roofers — releases significant quantities of fibres if regulatory precautions are not followed. An ordinary roofer cannot legally handle these materials without specific protective equipment and procedures.

Technical works (plumbing, electrical, heating)

Interventions on technical installations represent a frequently underestimated risk. Heating, hot water and steam pipes in buildings from the 1960s–1980s are frequently surrounded by asbestos-based lagging insulation: moulded asbestos shells, asbestos tape, asbestos felts. Simply removing this insulation to access pipes is sufficient to trigger the diagnostic obligation.

The scope of investigation: targeted, not exhaustive

A key difference distinguishes the pre-works diagnosis from the pre-demolition diagnosis.

Pre-works diagnosis: targeted scope

For the pre-works diagnosis, the inspection focuses on the zones and materials likely to be disturbed by the planned interventions. If you plan to redo only the first-floor bathroom, the diagnosis covers the materials of that room and adjacent surfaces potentially impacted — not the entire building.

This targeted approach is more economical and more operational. It allows the necessary information to be obtained quickly for the start of the construction site.

Important: define the scope precisely from the outset

If the works extend during the project to zones not covered by the initial diagnosis, an update or extension is required before continuing. This is why it is advisable to define the overall scope of works in advance and include a safety margin in the diagnostic mission.

Pre-demolition diagnosis: exhaustive inventory

For a demolition — even partial — the inventory must cover the entire building or the part to be demolished, without scope restriction. Full details are on the asbestos diagnosis before demolition page.

The asbestos report and building permit: cantonal specificities

In the canton of Vaud

The canton of Vaud requires that the asbestos diagnostic report be submitted with the building permit application for any renovation project on a building predating 1991. Several practical rules apply:

• The validity of the report is limited to 3 years: beyond this, a new diagnosis is required if works have not started.
• For major projects, a remediation plan drawn up by a FACH level 2 expert may be required in addition to the diagnostic report.
• The list of FACH-certified diagnosticians recognised by the canton is available on the cantonal portal vd.ch.
• Vaud municipalities may impose additional requirements under their building regulations.

In the canton of Geneva

The canton of Geneva has a particularly strict application framework:

• The asbestos verification obligation applies even for works that do not require a building permit — for example, routine maintenance work on old buildings.
• The Air, Noise and Non-Ionising Radiation Service (SABRA) is the competent authority for controlling decontamination sites.
• Decontamination sites are subject to strict prior notification rules, with the possibility of unannounced inspections.
• For projects subject to building authorisation, the asbestos report is required from the outset of the application process.

Important: Even when not formally required by the permit-issuing authority, the asbestos report will be requested by any serious company before starting work. Without this document, no responsible professional contractor can commit their employees to the site.

3 detailed practical cases

Case 1 — Renovation of a Geneva apartment (bathroom + kitchen, 1972 building)

Context: An owner wishes to completely redo the bathroom and kitchen of their co-owned apartment located in a 1972 building in Geneva city. They plan complete replacement of tiles, bathtub, shower tray, kitchen worktop and floor coverings.

Diagnostic result: The adhesive under the bathroom tiles contains chrysotile asbestos at approximately 5%. The 30×30 cm vinyl floor tiles in the entrance and corridor are also asbestos-containing, as is their laying adhesive. Interior renders reveal no asbestos fibres.

Practical consequences: A decontamination company is commissioned to remove the tiles with their adhesive and the vinyl tiles with their laying adhesive, under respiratory protection and partial containment. Waste is packaged in airtight bags and disposed of through a licensed channel. This preliminary removal takes two days. Standard renovation works then start without constraint.

The cost of the absence of a diagnosis: The tiler would have detached and fractured the tiles and adhesive, releasing fibres in a confined space — direct health risk for the tradesperson and occupants of neighbouring apartments. Site stoppage, emergency intervention, significant extra costs, owner’s liability engaged.

Case 2 — Roof renovation in Lausanne (fibre cement, 1965 building)

Context: An owner wishes to renovate the roof of their single-family home in Lausanne. The existing covering consists of corrugated grey sheets installed when the building was constructed in 1965.

Diagnostic result: The corrugated sheets are asbestos-containing fibre cement, confirmed by PLOM analysis. The general condition is moderate — a few cracked sheets, moss and lichen present — but the sheets are not in an advanced state of decay. The gutters and downpipes are also asbestos-containing fibre cement.

Practical consequences: The commissioned roofer must be a company authorised to handle non-friable asbestos-containing materials. The sheets are manually removed without cutting, protected and packaged in sealed big-bags, then disposed of through a licensed channel for special waste. A waste tracking document is established. A standard roofer without authorisation cannot legally carry out this work.

The cost of the absence of a diagnosis: An uninformed roofer would have broken the sheets and worked without appropriate equipment, exposing themselves and neighbours. Criminal liability of the owner, the roofer and their employer.

Case 3 — Transformation of a commercial premises in Carouge (vinyl floors, false ceilings, 1978 building)

Context: An investor wishes to transform a commercial premises on the ground floor of a 1978 building in Carouge into offices. The works plan to remove false ceilings, replace floor coverings, create new partitions and bring electrical installations up to code.

Diagnostic result: The false ceiling tiles contain asbestos at low concentration (chrysotile). The vinyl floor tiles are asbestos-containing. The tile laying adhesive is asbestos-containing. A sample taken from the render on the metal ceiling beams reveals asbestos sprayed coating at 15% — a very friable material, classified as high-risk.

Practical consequences: The asbestos sprayed coating on the metal beams is the absolute priority. Its removal is planned first, before any other work, under total containment and negative pressure, by a specialist team equipped with air-supplied respiratory protection apparatus. Removal of the false ceilings and asbestos floor tiles follows, with less demanding protocols than for the coating. The entire remediation plan is documented and submitted to Geneva’s SABRA. The renovation permit is processed once the report and plan have been validated.

The cost of the absence of a diagnosis: Tradespeople would have worked directly in the sprayed coating — the most dangerous asbestos exposure scenario. Massive fibre exposure, risk of serious long-term disease, criminal and civil liability of the client and companies.

Common errors and their consequences

”My building was partially renovated, so there is no more asbestos”

A prior partial renovation only removes the obligation for zones that have actually been treated and documented. If you are working in a zone not covered by a recent diagnosis or documented decontamination, verification remains mandatory.

”The building was constructed in 1989, just before the ban, so the risk is low”

The ban came into force on 1 March 1990. Materials produced and stocked before that date were still installed afterwards. A building delivered in 1991 may well contain asbestos-containing materials produced before the ban. The rule for buildings constructed “before 1991” incorporates this reality.

”The client told me there was no asbestos”

The word of the owner, an estate agent or a previous tenant has no legal value in asbestos matters. Only a diagnostic report established by a FACH-recognised specialist constitutes admissible proof.

”I am using a trusted professional who will be able to detect asbestos visually”

Asbestos cannot be detected visually in the vast majority of cases. Asbestos-containing tile adhesive, asbestos-containing render or asbestos-containing floor tile are visually identical to their non-asbestos equivalents. Only laboratory analysis allows confirmation.

Warning: Discovery of asbestos during a construction project — without prior diagnosis — requires the immediate stoppage of works in the affected zone, urgent commissioning of a diagnostician, then a decontamination company, and managing the health implications for workers already exposed. The extra cost compared to a preventive diagnosis is generally very significant. And the criminal liability of the client is engaged.

FAQ — Asbestos diagnosis before work

Is the diagnosis mandatory if the building has already been partially renovated?

Yes. A prior partial renovation only removes the obligation for zones that have actually been treated and documented by a diagnostic report. If you are working in a zone not covered by a recent diagnosis, verification remains mandatory.

What happens if the diagnosis is negative — no asbestos found?

A “negative” report has important legal and operational value: it documents that the zones concerned have been verified by a specialist and do not contain asbestos. This is the document you provide to companies and authorities to demonstrate that you have complied with your legal obligation.

Can I carry out several successive diagnoses as the project progresses?

Yes. For phased projects, the diagnosis can be conducted in several stages, each covering the zones concerned by the corresponding phase of work. However, it is more efficient to define the overall scope of works from the outset and carry out a comprehensive diagnosis to avoid costly back-and-forth.

Is the diagnosis valid for all companies working on the site?

Yes. The asbestos diagnostic report is a document attached to the property, not to the company. It can be provided to all companies commissioned for the site and is valid for all contractors working in the covered zones.

How far in advance should the diagnosis be ordered?

Ideally, the diagnosis should be ordered well in advance so that results are available before works commence. Given laboratory analysis turnaround times (5 to 10 working days), allow at least 2 to 3 weeks before the planned start date — more if your project requires a building permit.

Do you have a construction project on an old building in Western Switzerland? Call us on +41 58 590 91 92 or visit the asbestos diagnosis quote page to receive a proposal tailored to your situation. To understand the complete legal framework and sanctions, the mandatory asbestos diagnosis page details all obligations applicable in Geneva and the canton of Vaud.