Approved Document G - UK Sanitation and Water Efficiency Standard
Approved Document G is the UK Building Regulations standard covering sanitation, hot water safety, and water efficiency. It ensures adequate sanitary facilities, safe hot water temperatures, and water conservation in all building types across England.
Overview
Approved Document G is part of the UK Building Regulations and provides practical guidance on meeting the requirements for sanitation, unvented hot water systems, and water efficiency. The document sets standards for the provision of sanitary conveniences (toilets, washing facilities), wholesome water supply, and hot water safety to prevent scalding. It also establishes maximum water consumption limits for new dwellings to promote conservation. Approved Document G applies to all building work in England and works in conjunction with other Approved Documents (particularly Document H for drainage). The document specifies requirements for G1 (cold water supply), G2 (water efficiency), G3 (hot water supply and systems), G4 (sanitary conveniences and washing facilities), and G5 (bathrooms and kitchens/food preparation areas). Updated periodically to reflect technological advances and policy changes, the 2024 amendments consolidate current requirements emphasizing water conservation and Legionella prevention.
Key Features
- Minimum standards for sanitary facility provision based on building use and occupancy
- Hot water safety requirements to prevent scalding, particularly for vulnerable users
- Unvented hot water system installation and safety device specifications
- Maximum water consumption limits: 125 litres per person per day standard, or optional 110 litres when specified by planning permission
- Wholesome water supply standards and backflow prevention requirements
- Legionella risk mitigation in hot and cold water systems
- Accessibility requirements for sanitary facilities (referenced to Approved Document M)
- Water fitting regulations compliance and WRAS approval requirements
- Water consumption calculated using 'Water Efficiency Calculator for New Dwellings'
Applicability
Approved Document G is primarily used by:
- Plumbing engineers and designers for domestic and commercial sanitation design
- Registered plumbers installing unvented hot water systems and sanitary facilities
- Building control officers for plan approval and site inspections
- Architects for space planning and facility provision
- Approved inspectors for private building control certification
- Developers and builders for compliance with Building Regulations
- Water efficiency consultants for sustainability assessments
Geographic Application: Applies to England. Wales, Scotland, and Northern Ireland have separate but similar building regulation systems with comparable requirements.
Comparison Notes
- Complements Document H - Document G covers sanitation and water supply; Document H addresses drainage and waste disposal
- More prescriptive than US codes - Specific requirements for hot water temperatures and water consumption limits
- Unvented system focus - Detailed provisions for unvented hot water cylinders, common in UK but less so in US
- Water efficiency emphasis - Stricter water consumption limits than many international codes
- Integration with Water Regs - Works alongside Water Supply (Water Fittings) Regulations 1999
Official Source: https://www.gov.uk/government/publications/sanitation-hot-water-safety-and-water-efficiency-approved-document-g