How do I deal with unexpected defects during a renovation?

Strategies for dealing with the unforeseen

Root cause analysis: Where do the problems originate?

To react appropriately, one must understand why defects occur during renovations in the first place. Most often, it's not due to shoddy workmanship by the current tradespeople, but rather to "legacy issues." Classic examples . Causes of defects Renovations are :

• Historical building mistakes: In previous decades, buildings were often constructed with materials that are now considered problematic (e.g., asbestos, lead pipes). These defects only become apparent during renovations when the building structure is significantly altered.
• Hidden moisture: A leaking pipe that has been dripping for years without leaving any traces on the surface often leads to massive defects in masonry renovations once the wall is opened.
• Structural interventions: Sometimes it turns out that a wall which, according to the plans, should not be load-bearing, does in fact have a supporting function. Such Defects Renovations require immediate Act one Engineers .

Understanding that renovation problems are often rooted in the history of the house helps you to remain objective and not immediately look for someone to blame.

The emergency plan: How to react correctly

As soon as defects are discovered during renovations, construction must stop at the affected area. The most important step when defects arise is documentation. Take photos, lots of photos. From different angles, using a tape measure for size comparison . Complete documentation of the defects will be invaluable later on, should disputes arise with insurance companies or previous owners.

Inform the site manager or architect immediately. Do not attempt to fix defects yourself or pressure the contractor to "just tile over them." Concealing defects will backfire doubly later. A reputable contractor will provide you with a written report. This transparency is crucial for assessing the extent of the defects .

Legal situation: Who pays the bill?

This is where emotions often run high. Who is liable for defects in renovations that suddenly appear? In Switzerland, the principle of "owner's risk" generally applies. If you're renovating an old house and come across rotten beams , that's your risk as the owner. This type of defect in renovations isn't the fault of the tradesperson, so you have to pay for the repairs.

The situation is different if the tradesperson causes new defects or renovations through their work (e.g., accidentally drilling into a pipe). In this case, they are liable. However, with classic "hidden defects" (ground conditions, environmental contamination), you'll be stuck with the costs. Be sure to check your purchase contract carefully. Was the warranty waived ("sold as seen")? If so, you have little chance of holding the previous owner liable for defects or renovations , unless they deliberately concealed them. Proving deliberate concealment of defects or renovations , however, is very difficult in court.

Supplementary offers and cost control

As soon as defects arise during renovations, additional costs are incurred. The tradesperson cannot simply bill for these. He must provide a cost estimate . Supplementary offer create . For you, that means :

• Get a written quote for the cost of repairs and renovations .
• Check whether these costs are proportionate .
• the work to rectify the defects and carry out the renovations in writing.

Anyone who verbally says "Yes, go ahead" here often gets a shock when the final bill arrives. The costs for remedying defects and renovations must be controlled just as strictly as the main budget.

Prevention: The cushion in the budget

You can't prevent defects in renovations , but you can mitigate their financial impact. The most important tip for every homeowner is: plan for a reserve. Experts strongly recommend setting aside a buffer of:

• 10% for new builds/ new properties
• 20–25% in the budget for older buildings.

stretch their budget to the limit without considering potential defects in renovations risk having to halt construction. If no defects arise, you'll end up with money left over – a more pleasant problem to have. But always assume that some defects will be needed for renovations . Furthermore, a thorough preliminary analysis (e.g., asbestos check, moisture measurement) before construction begins helps minimize the risk of late-stage defects and renovations . The more you know beforehand , the fewer surprises you'll encounter later.

Communication is key.

Dealing with defects during renovations is also a matter of psychology. Seek dialogue with the tradespeople. Don't blame them for the condition of the building. When tradespeople realize you're solution-oriented , they're often more motivated to work on resolving the issues. Regular site meetings help identify minor defects early on, before they escalate into major problems. Document these meetings. A site log serves as your assurance that defects were discussed and who is responsible for what and by when.

Conclusion

Renovation issues are frustrating, but almost unavoidable in existing buildings. The key to success lies in mental and financial preparation. Accept that renovation issues are part of the process. Those who budget with a realistic risk buffer of 20% can sleep soundly even if renovation issues arise .

Formalities are crucial: Document all defects immediately, insist on supplementary quotes, and clarify the causes before construction continues. Don't let yourself be pressured into hasty decisions. A proper remediation of defects might take an extra week, but it will last for decades. Ignored defects will eventually resurface – and then it will become very expensive.

If you are looking for support with construction management or need tools to safely manage your budget including risk buffers, Loft offers professional solutions for this.

Glossary

• Renovation defects: A collective term for errors in the building structure or workmanship that are discovered or arise during a renovation.
• Owner's risk: The principle that the owner is liable for the condition of their property and building. The owner usually bears the costs of renovations for defects discovered by chance.
• Supplementary offer: An additional offer from the tradesman for work not included in the original contract (e.g., to rectify defects, renovations ).
• SIA Standard 118: Swiss standard work for construction contracts. It regulates the handling of remuneration, defects and deadlines for defect-related renovations .
• Unforeseen circumstances: A budget item (reserve) specifically reserved for unexpected renovations due to defects .