What role do renovation costs play in old buildings?

Overview of renovation costs for old buildings

If you completely renovate an old Swiss building, you must expect costs of between 1,500 and 2,500 CHF per square meter of net living space in 2026. While pure maintenance costs (value maintenance) are fully deductible for tax purposes, value-increasing investments (increasing comfort) can lead to an increase in the net rent. Energy-related measures such as heat pumps or façade insulation are supported by cantonal subsidies, which often cover 15% to 25% of the investment sum.

The cost structure: maintenance vs. added value

Anyone who owns an old building or is planning to buy real estate in Switzerland must understand the accounting distinction between maintaining value and increasing value. This differentiation is the basis for tax optimization and rent planning.

1. Value-maintaining measures (maintenance)

These are works that restore the property to its original state.

• examples: Painting work, repairing a broken roof, replacing the old oil heater with an equivalent model.
• tax advantage: In Switzerland, you can deduct these costs directly from your taxable income.
• tenancy law: Maintenance costs must not be passed on to the tenant; they are already included in the basic rent.

2. Value-enhancing measures (investment)

This involves work that increases the standard of the apartment or improves the residential value.

• examples: initial installation of a lift, enlargement of balconies, installation of a modern luxury kitchen.
• tax: These costs are not income tax deductible, but reduce property gains tax if sold at a later date.
• tenancy law: These investments entitle the landlord to increase the rent.

The energy-efficient renovation requirement 2026

The role of renovation costs has changed massively as a result of ecological change. In the past, renovation was often an aesthetic choice; today, it is an economic necessity in order to keep service charges under control.

The biggest cost blocks in check

Make sure that you have marked the following items in bold when calculating:

• building envelope (roof/façade): Comprehensive insulation for a single-family home often costs between 80,000 and 150,000 CHF. However, it is the basis for all further measures.
• heater replacement: Switching from oil/gas to a heat pump (air-water or geothermal probes) costs 35,000 to 65,000 CHF.
• windows: Replacing it with triple glazing costs around 1,500 to 2,500 CHF per window.

Strategy instead of coincidence: restructuring for landlord

For landlord in Switzerland, restructuring is a balancing act. On the one hand, it increases market value, and on the other hand, it must remain sustainable for tenants.

The two-thirds rule for energy-efficient renovations

• Swiss tenancy law is specific here: Energy-related renovations are considered “mixed” measures.
• Share of increase in value: In the case of comprehensive energy-related renovations, a share of 50% to 70% is generally recognized as adding value.
• Overwhelming: Only this value-adding share may be used to increase rent.
• Benefit for tenant: Although the net rent is rising, heating costs often fall in service charges, which dampens the gross burden.

Regional aspects: monument protection and building permit

Zurich doesn't stop at Bellevue, and not all old buildings are the same. Anyone building in a protected core area must expect massive cost jumps.

Cost case for monument protection

In many Swiss cities, old buildings are subject to monument protection or townscape protection.

• editions: Special materials (e.g. hand-painted glass, copper gutters) can increase material costs by 30% to 50%.
• planning: Approval procedures take longer, which drives up financing costs (construction loan interest rates).
• tip: As part of your tenant due diligence or buyer review, always clarify the protection status in cantonal inventory.

Conclusion: System beats luck in renovation

The renovation costs of old buildings are now the decisive lever for returns and the quality of life. Anyone who blindly buys a charming “property with potential” without knowing the 2026 energy roadmap is risking their capital.

In summary, it can be stated that anyone who plans their renovation digitally, makes use of cantonal funding and precisely calculates the difference between value retention and increase in value, makes the old building a successful project. In 2026, a well-renovated old building is more stable in value than many standard new buildings. Use the data power of modern portals such as heyloft.ch to find properties where the renovation ratio is right — with the right strategy, your match for a sustainable home is within reach.

glossary

• reference interest rate: The key indicator for your rent structure. It also plays a central role in calculating the allowable rent increase following renovations.
• Buying doesn't break rent: Your legal protection (Art. 261 OR). Even after a renovation and sale of the property, your rental agreement remains valid, except for urgent owner's own use.
• Tenant due diligence: Your personal due diligence Before moving into an old building, analyze the latest renovation report and utility bills to predict future rent jumps or high heating costs.