Part G
Plain English. Practical detail. UK context.
Part G is England's Building Regulations provision on sanitation, hot-water safety and water efficiency. It covers more than a bathroom's appearance or a cylinder's capacity. Approved Document G supplies guidance on relevant water supplies, fittings and safety arrangements for the building and work within its scope.
Last reviewed: (editorial review against the public sources listed below).
Plan the water service and intended use
A new dwelling, bathroom alteration or hot-water installation can raise different questions. Suitable water supplies, sanitary accommodation and washing or food-preparation arrangements need coordination with the building's actual use. Homeowners should explain the proposed fixtures and demand rather than choose a cylinder by size alone. Tradespeople need the relevant design and service information before installation. Water Fittings requirements, drainage guidance and other duties may also apply. Satisfying one provision should not be presented as proof that every supply, backflow or discharge arrangement has been resolved.
Hot-water safety is a designed system
Storage, temperature and pressure control, safety devices and suitable discharge arrangements need appropriate competence and the actual system detail. An unvented cylinder is not a casual substitute for another vessel simply because it fits the space. Trainees should understand the limits of their role and obtain instruction before working on safety-related components. This reference supplies no valve setting, discharge-pipe recipe or universal pressure. A qualification or product course should match the tasks; it is not permission to modify every protective arrangement or ignore manufacturer instructions.
Efficiency and convenience are not the same claim
Approved Document G includes water-efficiency guidance and defined calculation or fitting approaches for relevant work. Do not treat a low-flow label on one tap as proof that the whole dwelling meets its target. Applicable optional requirements and project conditions need checking. Homeowners may have preferences for baths, showers or controls that affect the specification. Trainees should learn how product choices transfer into the agreed design and records rather than substitute a fixture for appearance alone. Energy and ventilation requirements also need coordination without conflating them with water-use compliance.
Handover should explain normal use and limits
Agree the supply, equipment, controls, drainage or discharge interfaces, testing, documentation and making good. Identify who handles approval or notification and specialist work. Explain normal operation, maintenance and when to seek competent help; do not encourage occupants to adjust safety devices. HSE guidance informs safe installation and material handling. No typical UK cylinder cost or guaranteed water saving is stated because these sources do not establish one universal package. England's guidance is not a substitute for the other UK nations' frameworks. Keep relevant product, design and commissioning records together so later work can identify the intended arrangement.
Frequently asked questions
Does a water-efficient tap prove whole-dwelling compliance?
Not by itself. Follow the applicable complete calculation or fitting approach.
Can any plumber alter every unvented safety arrangement?
Only with the relevant competence and an appropriate specification; protective components are not casual adjustment points.
Sources and further reading
Public sources and further reading. Sources checked: 8 November 2026. Consult the original for details and later changes.