Part G Water Efficiency Calculations

Approved Document G of the Building Regulations sets a maximum internal water consumption target of 125 litres per person per day for new residential buildings. Water calculations must be submitted to building control as part of the compliance process for all new-build dwellings in England and Wales.

The calculations assess combined consumption of all water-using fittings — baths, showers, basins, toilets, and kitchen appliances — confirming the building meets the regulatory target. Some LPAs or sustainability schemes may require the enhanced 110 l/p/d target.

Our Part G Water Calculation Services

• Water efficiency calculations in accordance with Approved Document G
• Assessment against the standard 125 l/p/d target and enhanced 110 l/p/d target
• Full documentation prepared and formatted for building control submission
• Advice on compliant fittings and appliance specifications
• Fast turnaround to support your project programme