What are the most common apartment renovation mistakes?

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An apartment renovation rarely goes exactly to plan. But there is a difference between surprises you cannot anticipate and mistakes that repeat themselves in almost every renovation — and that could have been avoided.

Starting a renovation without a project

The biggest mistake is also the most common: starting a renovation without a functional layout and technical drawings. Without a project, decisions are made on the spot — by the contractor, under pressure, in real time. The result is outlets in inconvenient positions, installations reworked mid-renovation, and additional construction work you had budgeted neither time nor money for. Technical drawings are not a luxury — they are the instruction set every contractor works from.

Underestimating the budget

Most renovations exceed their budget not because materials are expensive, but because the original budget did not include everything. Transportation costs, additional material quantities, unforeseen repairs to existing installations — it all adds up. Good practice is to plan a reserve of at least 10–20% on top of the total, and to treat it not as money to spend but as a buffer for reality.

Electrical installation mistakes

Electrical work is planned once — and then covered up. That is precisely why mistakes here are so costly to correct: too few outlets, switches in awkward positions, appliance connections that don't align with where the furniture actually ends up. Many outlets eventually end up behind the sofa or the bed — and stay there for years, accessible only when you move the furniture. A well-prepared electrical plan accounts for the specific appliances, their locations, and how they will be used — not just the number of points.

Improper plumbing planning

Plumbing errors are perhaps the most expensive to correct after a renovation is complete — because fixing them means breaking up already-laid tiles or screed. Incorrect sink positioning, connections that don't match the actual dimensions and installation type of the appliances, inappropriate pipe heights — all of this needs to be resolved before work begins, not during it.

Poorly planned lighting

Lighting is one of the things most easily overlooked during planning — and most strongly felt in daily life. A single fixture in the middle of the ceiling is not a lighting plan. Well-planned lighting distinguishes three functions: general lighting for the overall space, task lighting for specific zones such as a countertop or desk, and accent lighting for atmosphere. The scheme is designed alongside the electrical plan — after that, it is too late to make changes without tearing things apart.

Choosing materials based only on appearance

A tile that looks good in the showroom may be difficult to maintain, unsuitable for underfloor heating, or dangerously slippery in a bathroom. A floor chosen purely for its colour may not hold up to heavy use. Choosing materials requires considering the function of the space, how it will be used, and long-term durability — not just the visual result.

Lack of coordination between contractors

A renovation typically involves multiple specialists — a builder, an electrician, a plumber, a plasterer, a tiler. Without written documentation, each one works according to their own interpretation of what needs to be done. When something goes wrong, responsibility gets shifted, work gets redone, and the project runs late. Clear documentation is not bureaucracy — it is the only way different contractors can work toward the same outcome.

Key Takeaways

• Don't start a renovation without technical drawings and a functional layout.
• Plan a reserve budget of at least 10–20%.
• Plan electrical, plumbing, and lighting before construction starts.
• Choose materials based on functionality and durability, not just appearance.
• Ensure clear documentation for all contractors — it is the foundation of coordination.