PART G · Water and sanitation
Part G building regulations explained
Part G covers water supply, hot water safety, sanitation and water efficiency. It affects the design of bathrooms, kitchens and water systems. A room can look finished while still having unresolved issues with safe temperatures, sanitary provision or installation records.
What does Part G cover
The six requirements address cold water supply, water efficiency, hot water systems, sanitary conveniences and washing facilities, bathrooms, and kitchens or food preparation areas.
Some requirements depend on the type of work. In particular, the water efficiency provisions for new dwellings should not be described as a universal consumption limit for every existing household.
Why hot water needs careful design
Stored hot water involves temperature, pressure and discharge arrangements. Safe provision depends on the system as a whole, including controls and protection against failure.
Ask the installer to identify the system, the appropriate certification route and the operating information you will receive. Do not change safety controls to solve a comfort problem without competent advice.
What matters when moving a bathroom
Plan water supply, waste routes, ventilation and maintenance access together. Part G works alongside Part H drainage and Part F ventilation.
For example, locating a bathroom far from existing services may affect the layout and installation cost. Resolve those routes before ordering fittings.
What should you keep at completion
Retain relevant design information, installation certificates, water efficiency calculations where required and instructions for controls and maintenance. Check that important valves and service points remain accessible.
For non-domestic toilet projects, Part M accessibility and Part T toilet accommodation may also apply. An attractive sanitary layout is not enough if users cannot reach or use it, or if the wider requirements have been overlooked.
Ask the designer which requirements apply to the project and record the answer on the drawings and specifications.