Renovating an old house: 2026 costs, process and what to watch out for

Renovating an older house is now the most common path to home ownership: the plot and the structure already exist, which is a huge advantage. But houses from the 1930s–1980s hide more below the surface than a first viewing shows. Here is a realistic look at prices, process and risks.

How much does renovating an old house cost in 2026?

A 150 m² house thus comes to roughly CZK 2.1–3 million excl. VAT for a complete renovation. The condition of the structure always decides — which is why our site survey and itemised quote are free.

The right order of works

1. Survey and design: statics, damp, roof timbers, services — budget only after that.
2. Demolition and remediation: strip-out, drying the masonry, treating roof timbers.
3. Roof and windows: the building envelope must be tight before investing inside.
4. New services: wiring, water, drainage, heating.
5. Facade insulation, plasters, screeds.
6. Fit-out and finishes: bathrooms, kitchen, floors, painting.

Hidden defects older houses tend to have

• Damp in the foundations — houses built before the 1960s almost never have damp-proofing; remediation costs tens to hundreds of thousands.
• Aluminium wiring — full replacement needed (about CZK 1,700/m² of floor area).
• Infested roof timbers — rot or woodworm only shows after opening up; keep a reserve.
• Old risers and cast-iron drainage — always replace while the walls are open.
• Non-standard ceilings (timber beam) — limit layout changes; a structural engineer decides.

Golden rule: add a 15–20% reserve to an old-house budget for hidden defects. If you don't spend it, all the better.

Renovate, or demolish and build new?

A rough guide: when the repair exceeds 70% of the cost of a new build and the house has no layout or historic value, demolition and a new build (from about CZK 31,000/m²) tends to be more economical. Below that threshold, renovation usually wins — especially with sound foundations and roof structure.

A first number in 2 minutes

Estimate your renovation budget in our online calculator — choose "Renovation", enter the area and scope. You will then get an exact itemised quote after a free, no-obligation site visit.