Construction damage report in Switzerland: cause, liability and cost
Summary: A construction damage report establishes what exactly the damage is, where it comes from, who is liable and what the repair will cost. It secures the condition before any repair work and is the basis for an effective defect notice, for negotiations with the contractor or for the insurer. Timing is decisive: anyone who repairs first and has the damage assessed afterwards often has nothing left to prove. Since 2026, a notice period of 60 days from discovery applies to new contracts.
This article explains when a damage report for construction defects in Switzerland makes sense, what it must contain, how it differs from a party expert report and a defect list, which deadlines apply and what it costs. I write from my practice as an SIA architect who assesses construction damage and supports owners with defects. As at October 2026.
Contents
One photo is enough for the first step
Send me photos of the damage. You will receive an initial assessment of whether the contractor is liable and what to do now.
1. What a damage report is
A damage report is a written professional investigation of construction damage. It answers four questions: What exactly is the damage? What is the probable cause? Is there a defect within the meaning of the construction contract, and who is liable for it? What will the repair cost?
What a construction damage expert delivers differs from a simple inspection mainly in the documentation. A damage report records the condition with photos, dimensions, measured values and plans in such a way that third parties can follow it too: the contractor, its insurer, a lawyer or later a court. At the same time, it assesses professionally whether the work complies with the recognised rules of building practice, the SIA standards and the contract.
A damage report is not a judgment. It is a sound basis you can rely on. And it is honest: if damage is due to improper use, lack of maintenance or normal ageing, the report says so. That spares you a dispute you cannot win.
2. Typical reasons for a damage report
In my practice, damage reports are needed above all in these situations:
Water and moisture: Damp walls in the basement, water entering during heavy rain, leaking flat roofs, terraces or balconies.
Mould: In new flats often a question of construction moisture, ventilation or thermal bridges. In rented flats, also the question of whether tenant or landlord is responsible.
Cracks and settlement: Cracks in walls, ceilings or facades, a terrace or driveway that is sinking, floor slabs that are moving.
Defects after handover: Defects that only become visible after the property handover and are disputed by the contractor.
Damage caused by neighbouring construction: Cracks or settlement that appear during a building project next door. Here, above all, a record of the condition before construction starts helps.
Building services: Pipes, heating, heat pumps or ventilation that do not work as agreed or cause consequential damage.
What all cases have in common: there is visible damage, a disputed or unclear cause and at least one party that does not want to pay. That is exactly where a report creates clarity.
3. Damage report, party expert report, defect list: the differences
Several terms are often confused in construction. The most important differences:
Document | Purpose | When |
Defect list | Record defects at handover | At handover |
Defect notice | Assert a defect against the contractor | Within the deadline after discovery |
Damage report | Establish cause, liability and cost of damage | With disputed or unclear damage |
Check a building permit or project under building law | In an objection or appeal | |
Court-appointed report | Technical question in litigation, ordered by the court | In proceedings or as a precaution |
Defect notice and damage report belong together. The notice is the legal declaration that a defect exists and that you are asserting your rights. How to do this correctly is explained in the article How to claim construction defects in Switzerland. The report provides the professional evidence for it, especially when the contractor disputes the defect or its responsibility.
Party expert report is, legally speaking, the umbrella term for any report that a party commissions itself. A damage report you commission is therefore also a party expert report. In everyday use, however, a party expert report in building law usually means the review of a building permit in an objection or appeal. That is the subject of the article Party expert report in Swiss building law. Anyone who needs an independent assessment before a purchase or before signing a contract is better served by a second opinion.
4. Why timing is decisive
The most common mistake with construction damage is not the wrong notice but the wrong sequence. Many owners have damage repaired first and only ask afterwards who pays. By then the evidence is gone.
After repair, the cause often cannot be established: A freshly plastered wall no longer shows whether the moisture came from outside, from inside or from a pipe.
Damage changes: Cracks grow, moisture migrates, mould spreads. What is clear today will be unclear in three months.
The other side was not present: Phone photos show the damage but rarely the cause. A report with measured values, dimensions and an assessment is harder to dispute.
Deadlines run from discovery: Anyone who waits risks forfeiting their rights in respect of defects.
My rule therefore: secure first, then repair. Emergency measures that prevent further damage are of course allowed and often even required, such as a temporary cover or shutting off a pipe. Anything that permanently changes the condition waits until it has been documented. Inform the contractor in writing and give them the opportunity to inspect the damage themselves.
With a building project next door, the same applies the other way round: a crack survey before construction starts records the condition of your house. If new cracks appear during construction, the evidence is clear.
5. Deadlines and legal position since 2026
For contracts for work and land purchases, the legislator adjusted the rights in respect of defects as of 1 January 2026. WEKA gives a good overview of the changes to defect notices from 2026 (in German). The key points:
Topic | Contracts from 1.1.2026 | Older contracts |
Notice period for buildings | 60 days from discovery | Immediately after discovery |
Agreeing a shorter notice period | Invalid to the owner's detriment | Generally possible |
Limitation period for defect claims | 5 years, cannot be shortened | 5 years, can be shortened |
Right to remedial work | Mandatory and free of charge | Can be excluded by contract |
The statutory basis is found in the law on contracts for work, Art. 367 ff. of the Code of Obligations. What a defect in the work actually is, is explained by WEKA in a basic article (in German).
If SIA standard 118 has been agreed: A two-year notice period then applies after handover, during which you can notify defects at any time. If the contractor disputes a defect during this period, it must prove that there is none. After the two years have expired, hidden defects must be notified immediately after discovery, and the burden of proof shifts back to the owner. From that point on, a damage report becomes particularly important. More on this in the article Warranty and warranty periods in Switzerland.
So first check which contract applies and whether SIA 118 forms part of it. If you do not know, you will find the answer in the construction contract or the purchase agreement. What to look out for in contracts is set out in the article Construction contract review in Switzerland. For off-plan purchases, the article Buying a new build in Switzerland is the right complement. These notes are no substitute for legal advice. With tight deadlines or large amounts, involving a lawyer early is worthwhile.
6. What a good damage report contains
A damage report is effective not because of its length but because it can be followed. These elements belong in it:
Mandate and questions: Which questions are to be answered, and what is expressly not covered.
Documents: Contracts, building specification, plans, handover record, correspondence with the contractor, earlier notices.
On-site findings: Date, persons present, weather, photos with location and scale, measured values such as moisture, crack widths or gradients.
Cause analysis: Which causes come into question, which are probable, which can be ruled out and why.
Professional assessment: Does the work comply with the contract, building specification, SIA standards and recognised rules of building practice?
Measures and costs: How the damage is properly repaired, with a cost estimate and its accuracy.
Open points: What can only be clarified by further investigation, for example probing, a camera inspection or material testing.
The tone is just as important. A factual report that keeps findings and assessment clearly apart is taken more seriously by the contractor and its insurer than one that talks of botched work. And it also names the points that do not speak in the client's favour.
7. Process: from the first call to the report
Initial consultation: You describe the damage and send photos, contract and handover record. I tell you whether a report is needed or whether a notice is enough for now. Free of charge and without obligation.
Securing deadlines: If a notice period is running, I first help you file a precautionary notice so that no rights are lost. The report follows afterwards.
Inspection: On-site inspection with photos, measurements and survey. Where possible I invite the contractor, which strengthens the evidential value.
Evaluation: Comparison with contract, plans and standards, cause analysis, specialists involved where needed.
Report: Written report with photo documentation, assessment, measures and cost estimate.
Follow-up: On request, I support the negotiations with the contractor or check the remedial work.
With complete documents, the report is usually ready within one to two weeks of the inspection. If it is urgent, for instance because of a deadline or an imminent repair, I give the inspection priority.
8. What a damage report costs
The cost of a damage report depends on the effort. I charge by actual effort at CHF 180 per hour, with an estimate of effort in the quote. On request, I set a cost ceiling.
Scope | Typical effort | Indicative cost |
Short on-site assessment with brief report | 3 to 5 hours | CHF 540 to CHF 900 |
Damage report with cause and costs | 8 to 15 hours | CHF 1,440 to CHF 2,700 |
Several defects or complex causes | 15 to 25 hours | CHF 2,700 to CHF 4,500 |
Indicative figures, as at 2026, including the inspection in the Zurich area. Not included are services by specialist firms such as leak detection, sewer camera inspection, opening up building components or laboratory analyses. Depending on the effort, these cost a few hundred to a few thousand francs.
Whether you get the costs back depends on the individual case. If there is a defect in the work, the effort can often be claimed from the contractor as part of the loss. That is not guaranteed. Compared with repair costs that often run into tens of thousands of francs, an early report is usually money well spent, precisely because it can also show that a dispute is not worth it.
With me, damage reports are part of the second opinion and owner's advisory services.
9. When I recommend a court-appointed report
A damage report you commission yourself is, legally speaking, a private expert opinion. Since 1 January 2025, it counts as documentary evidence in civil proceedings and is assessed freely by the court. A report ordered by the court itself, however, carries more weight.
If litigation is foreseeable and the other side disputes the damage in principle, a precautionary taking of evidence under Art. 158 of the Civil Procedure Code can make more sense. Here the court appoints an expert before the actual proceedings to establish the condition. The requirement is that evidence is at risk or that you can credibly show an interest worthy of protection. The procedure is more expensive and slower, but the result is harder for both sides to challenge.
In practice, the private report is often the first step: it shows whether your position holds up. If the contractor then moves, the dispute is settled. If not, the report is a good basis for the lawyer and for deciding whether court proceedings are worthwhile.
10. Frequently asked questions about damage reports
What is a construction damage report? A construction damage report is a professional investigation of damage to a building. It records the condition, establishes the probable cause, assesses whether there is a defect within the meaning of the construction contract and estimates the cost of repair. It serves as the basis for a defect notice, for negotiations with the contractor or for the insurer.
When should I have a damage report prepared? As early as possible, and in any case before anything is repaired, patched up or covered over. After a repair, the cause can often no longer be established. For contracts concluded from 1 January 2026 onwards, a notice period of 60 days also starts running when a defect is discovered; for older contracts, defects must be notified immediately.
What does a damage report cost? A short on-site assessment with a brief report typically takes me 3 to 5 hours, i.e. CHF 540 to CHF 900. A full damage report with cause analysis and cost estimate takes 8 to 15 hours, around CHF 1,440 to CHF 2,700, charged at CHF 180 per hour. Measurements by specialist firms come on top. Indicative figures, as at 2026.
Who pays for the damage report? Initially the client. If there is a defect in the work, the cost can, depending on the contract and the negotiations, be claimed from the contractor as part of the loss. There is no guarantee of that. In insurance cases the insurer often investigates itself; your own report is mainly worthwhile if you do not share its assessment.
Is a damage report the same as a party expert report? Not quite. Every damage report you commission yourself is, legally speaking, a party expert report. In everyday use, however, a damage report means the investigation of construction damage, i.e. cause, extent and cost. A party expert report in building law, by contrast, checks whether a building project or a building permit complies with the regulations.
Is a damage report enough in court? Since 1 January 2025, private expert opinions count as documentary evidence in civil proceedings and are assessed freely by the court. A report obtained by the court still carries more weight. If litigation is foreseeable and the other side disputes the damage, a precautionary taking of evidence under Art. 158 of the Civil Procedure Code with a court-appointed expert can make more sense.
Have the damage assessed?
I assess the damage independently and tell you honestly what I see, even if the contractor is not responsible. Free initial consultation.
Comments