Ten-year structural warranty in Switzerland: myth, reality, and what your contract actually covers

Introduction

For an SME investing in real estate projects or business premises, understanding the legal and insurance protections after completion of construction is a matter of risk management. The term "ten-year warranty ," well-known in neighboring countries like France, can be confusing in Switzerland. This guide helps you decide: what legal obligations exist, what insurance policies to take out, how to document your rights, and what default scenarios you should anticipate, quantify, and monitor.

After reading this, you will be able to differentiate what is legally applicable in Switzerland, what falls under contractual clauses or private insurance, and how to structure coverage adapted to an SME project.

1. Swiss legal framework: what actually applies

1.1 Responsibility after acceptance of the work

Unlike the French model, Switzerland does not impose an independent statutory “ten-year warranty” applicable to all builders. The liability of contractors and project owners for construction defects arising from a construction contract is governed by the Swiss Code of Obligations (CO) and supplemented by technical standards such as SIA 118 , which are often incorporated into the contracts.

According to Article 371 of the CO, for real estate work, the client has a period of 5 years after acceptance to assert hidden defects affecting a fixed structure.

1.2 SIA Standards and Contractual Responsibilities

The standards of the Swiss Society of Engineers and Architects (SIA) — for example, SIA 118 — are frequently incorporated into contracts. They establish contractual obligations, including warranty periods for visible or hidden defects. They do not create a legally binding ten-year warranty, but rather reinforce a contractual framework defined with your partners.

Reference structure of responsibilities (without invented numbers):

Source of law	Deadline	Nature
Code of Obligations (CO)	5 years (defects after receipt)	Contractual liability
SIA standards (if integrated)	Contractual	Specific terms and conditions

2. Ten-year structural warranty insurance in Switzerland: products and realities

2.1 Private insurance vs. legal obligation

Insurance covering defects for up to 10 years is available in Switzerland as a private product, sometimes called " inherent defects insurance ." In other countries, this type of product is legally required; in Switzerland, it is a voluntary option that can be taken out to reassure buyers or investors about a project.

2.2 What these insurance policies can cover

When stipulated in a contract or taken out voluntarily, these insurance policies can cover serious defects that:

• compromise the structural integrity of the building,

• render the intended use impossible or improper ,

• concern essential structural elements (e.g. foundations, framework).

These are usually major technical defects, not minor aesthetic problems or mere superficial irregularities.

2.3 Builder's liability insurance

For construction companies, professional liability insurance remains a standard practice to cover design or execution errors during the contractual liability period. This insurance can be tailored to cover contractual commitments longer than those stipulated by the Swiss Code of Obligations (CO).

3. Practical Scenarios

Case study 1 – New building in SMEs

A small business has industrial premises built. The contract incorporates SIA standards and includes a contractual warranty period after acceptance. Three years after delivery, water infiltration appears in the load-bearing structure.

Decision to be made:

• Examine the expert report to determine if the defect was hidden upon receipt.

• Check the contractual clauses related to SIA standards (periods, exclusions).

• Examine whether a private “ten-year” insurance policy has been taken out and what it covers.

• Officially document the discovery, expert reports, correspondence.

• Determine if an action under contractual liability CO (5 years) is still possible.

Case study 2 – Major renovation

A small business undertakes a major renovation of an existing building. One year after completion, structural cracks appear.

Decision to be made:

• Document defects systematically by an independent expert.

• Compare the exclusions of the builder's liability insurance and any private insurance.

• Prepare the notifications within the prescribed deadlines.

• To decide between renegotiating repairs with the contractor or taking legal action.

4. Guidelines and checklist for decision-making

What needs to be documented

• List of defects observed

• Dated photos of the observed condition

• Independent expert report

• Construction contract and applicable SIA clauses

• Insurance policies (civil liability, private insurance)

• Notification letters sent

Pilot checklist

Stage	Objective
Defect identification	To observe the actual impact on the work
Analysis of contractual clauses	Check obligations & deadlines
Insurance verification	Determine which coverage applies
Official documentation	Structure for tracking & proof
Decision on stock	Choosing between an amicable or legal approach

5. Common mistakes and how to avoid them

Mistake 1 – Confusing “ten-year warranty” and CO2 liability

Many people believe that Switzerland imposes a 10-year warranty like France. In reality, the Swiss Code of Obligations (CO) stipulates liability for up to 5 years after delivery.

Solution: Read your contracts carefully and include insurance if necessary.

Mistake 2 – Neglecting fault documentation

Without a documented expert report, it is difficult to assert a right.

Solution: Involve an independent expert as soon as a defect is detected.

Mistake 3 – Underestimating the importance of SIA Standards clauses

Ignoring the integrated SIA clauses can leave gaps.

Solution: Check the SIA contractual annexes and the associated obligations.

6. Questions to ask your insurer/broker

1. Does this policy cover structural defects after acceptance?

2. What is the actual duration of contractual coverage offered?

3. What are the limits of the guarantees (ceilings, exclusions)?

4. Is this insurance linked to a specific SIA standard?

5. How are the defects covered in this contract defined?

6. What is the procedure for reporting a claim ?

7. What documents do I need to provide to validate a claim?

8. Is builder's liability insurance included?

9. Can the warranty be extended or transferred in the event of a sale?

10. What costs/deductibles apply in case of recourse?

Conclusion

For an SME in Switzerland, a ten-year structural warranty is not a legal requirement, but rather a contractual or insurance-based concept that can be beneficial depending on your exposure to construction risks. The applicable legal framework remains Swiss contractual liability (Swiss Code of Obligations) and the SIA Standards clauses. Private insurers may extend coverage to 10 years for serious defects, but it is up to you to decide whether this level of commitment is appropriate for your project.

Managing these risks means documenting them precisely , comparing your contracts and insurance policies , and defining clear decision thresholds for each potential default. Your next step: have your current coverage audited by a specialist to identify any gaps between your obligations and the protections in place.