Which standard applies to the installation of hot and cold water services inside domestic buildings?

• A. BSEN 806
• B. BSEN 806A
• C. BSEN 806-B
• D. BS EN 806

Answer: (A)

A unified standard governs how hot and cold water services are installed inside domestic buildings. BS EN 806 is the standard that covers the design, installation, testing and commissioning of water supply systems inside buildings, ensuring safety, hygiene and reliable performance for both hot and cold supplies. It specifies how pipes and fittings should be chosen and routed, how components are installed to prevent contamination and back‑flow, how inspections and tests are carried out, and how hot water systems are provided safely. Following this standard helps prevent issues like poor water quality, cross‑connections, or improper sizing and installation that could lead to leaks or scalding. Variants with suffixes (like A or B) aren’t separate standards for domestic internal installations, and the general BS EN 806 designation is the correct one to reference.