Renovating an older house: complete guide to cost and process

Renovating an older family house is one of the most demanding construction projects. Unlike a new build, you are working in unknown territory — a crack, damp wall or obsolete wiring may be hiding behind any plaster. Here is what a 2025 renovation costs and how to approach it.

How much does a house renovation cost in 2025

• Cosmetic renovation (surfaces, kitchen, bathroom): from CZK 8,000 / m²
• Mid-scale renovation (utilities, layout): from CZK 18,000 / m²
• Full renovation (incl. insulation, structural, roof): from CZK 30,000 / m²
• Renovation with extension or storey addition: from CZK 35,000 / m²

Prices include materials and labour. We provide an exact estimate only after a site survey — older houses tend to surface hidden structural issues.

Phases of a renovation step by step

1. Site survey and condition assessment

Before any pricing, the house must be professionally inspected. A surveyor assesses load-bearing structures, damp, structural condition and utilities. Removing load-bearing walls requires a structural assessment.

2. New layout and project documentation

The output is a layout study followed by authorised project documentation. If the renovation affects load-bearing structures, the facade footprint or the use of the building, a permit or notification is required.

3. Estimate and tendering

A detailed URS-based itemised estimate is your strongest defence against unplanned costs. A blank BoQ is then used to invite contractors to bid.

4. Construction

• Demolition — 1–2 weeks
• Shell works, new utilities, structural — 4–8 weeks
• Plastering, flooring, insulation — 3–6 weeks
• Finishes, bathrooms, kitchen — 4–6 weeks
• Cleaning, handover — 1 week

For a typical renovation, count on 3–6 months from first demolition to move-in.

5. Approval and handover

For permitted works, the procedure ends with an approval certificate. Before signing the handover, have all inspection certificates verified (electrical, gas, plumbing, chimney).

Most common mistakes

1. Starting without a project. "It's only a renovation" is the most expensive sentence in the trade.
2. Picking the cheapest contractor. Hidden change orders easily exceed the original saving.
3. Removing a load-bearing wall without a structural engineer. Risk of serious damage.
4. Underestimating utilities. Laying new floors over old pipes never pays off.
5. Skipping insulation. The ideal time is together with the facade renovation.

How to choose the right contractor

• Verify references on similar projects — not just photos but contacts.
• Insist on a detailed itemised estimate, not a lump sum.
• Check whether the company has its own structural engineer and designer.
• Liability insurance is a must for any serious studio.

How RUMASTAV handles renovations

At RUMASTAV we deliver renovations turnkey — survey, design, structural, estimate and execution. Clients have one contact and one accountable party instead of coordinating three to five separate suppliers.

Summary

A house renovation is an investment that deserves careful thought. The keys are quality design, a transparent estimate and an experienced contractor. Get in touch — we will visit for free and propose a realistic plan.