Water, drainage and ventilation in the building code

A wet room has to do more than shed water — it has to deliver clean water, carry waste away, and keep the air dry. BBR covers all three, and they're as important to a lasting bathroom as the membrane itself.

Water and drainage (section 6:6)

BBR requires water and drainage installations to be designed and installed so they provide safe water and remove wastewater without risk of damage or ill health. This is the legal basis the Säker Vatten plumbing rules build on — leak-safe routing, backflow protection, and hygienic hot and cold supply.

Ventilation and indoor air

BBR requires adequate ventilation to remove moisture and pollutants and keep indoor air healthy. In a wet room this is critical: extraction after every shower is what keeps humidity down and mould out. A beautifully waterproofed bathroom with poor ventilation will still grow mould and degrade its finishes — so the air matters as much as the surfaces.

Utility and technical rooms

For rooms with water heaters and similar equipment, BBR's general recommendations call for waterproof flooring, a floor gully with evaporation protection, and proper hot-water installation — so a leak has somewhere safe to go and the room can be maintained.

What M5 brings to Dubai

We treat plumbing, drainage and ventilation as part of the wet-room system, not afterthoughts — safe supply, proper waste, and extraction that actually keeps the room dry. In Dubai's humidity and heavy air-conditioning, good ventilation isn't optional; it's what protects everything else we build.

Official source: this is M5's plain-language summary, not the official text. For the full regulations see Boverket — boverket.se.