How to Build a Bathroom

Did you know that improper bathroom waterproofing is one of the most common reasons homeowners have to undertake renovations costing thousands of euros? In 2026, technical requirements and material selection have become even more precise, which is why every wet room construction requires thorough and informed preparation.

Permits and documentation

Your dream bathroom begins with correct documents and understanding of legislation. According to Annex 1 of the Building Code, when renovating a residential building where technical systems or load-bearing and stiffening structures are modified, you must submit a building project and building notice to your local municipality. If you are still considering whether to renovate or build a new house, keep in mind that thoroughly renovated and energy-efficient homes are particularly highly valued in the 2026 real estate market. Even if you plan only wall demolition in an apartment building, you should expect expenses of 500–2000+ euros and possible unforeseen additional work that could affect your budget.

Planning and budgeting

Thorough preparation will save you from future additional costs and ensure the functionality of the space for years to come. Begin bathroom interior planning with precise measurement of the space and design of traffic routes, which ensures ergonomic and comfortable use. For major renovations, it is prudent to plan for at least a 15% financial buffer, as replacement of old piping and electrical wiring may prove more complicated than anticipated. This is particularly relevant when undertaking how to renovate an old house, where the building's original condition determines the actual scope and cost of the renovation.

Waterproofing and moisture protection requirements

The foundation of a durable bathroom is proper waterproofing, which protects the building's structures from moisture damage. According to the current guideline RT 84-11166-et, waterproofing must be installed in at least two layers directly under ceramic tiles. You must pay special attention to the areas around drains and corners, where specialized feedthrough sleeves and reinforcing mesh must be used. To ensure smooth water drainage, the overall floor slope must be at least 1:100 and 1:50 in the immediate shower area. The same rigorous moisture protection principles are followed in the guide addressing sauna building best practices, where the quality of vapor barrier and insulation is of critical importance.

Technical systems and internal plumbing

Modern piping must comply with 2026 standards such as EVS 835 and EVS 921, which regulate the safety and reliability of water supply systems. As an owner, you are responsible for the proper condition of your internal plumbing, which is why it is worthwhile to choose insulation materials with a thickness of at least 9 mm to prevent pipe freezing near external walls. It is also important to follow practical advice on simple ways to prevent blockages at home, so that your new sanitary fixtures and plumbing remain in working order for decades without major repair costs.

Ventilation and healthy indoor climate

A healthy indoor climate requires efficient air exchange in the bathroom to maintain air humidity in the optimal range of 40–60%, which prevents water vapor condensation. The new standard EVS-EN 15780:2025 provides precise guidance for maintaining cleanliness of ventilation systems in both new and existing systems. Effective ventilation removes excess moisture before it can cause mold or damage the building's interior finishes. You can find more advice on indoor climate and system maintenance in a guide that explains how to prepare your plumbing and heating system for winter.

A thoughtfully designed bathroom is a long-term investment in your home's comfort and market value. By following technical standards and making informed choices from planning through to final finishing, you create a space that remains modern and safe for decades. If you are still looking for a suitable property to design to your liking, or wish to find real estate with modern solutions, you will always find the best offers and comprehensive market statistics at Kinnisvara24 portal.