Part G

A water efficiency calculation is a legal requirement under Part G of the Building Regulations (Approved Document G) and required for all new homes in England.   

These rules limit water consumption to no more than 125 litres per person per day.  Some local planning authorities set stricter targets of 110 litres or less, particularly in areas that are considered water stressed.

Water Efficiency Calculations predict a new property's total water consumption.  This is to ensure it meets regulatory standards and promotes water conservation by assessing flow rates and capacities of various fittings and appliances, such as taps, showers, and toilets.   The calculations verify that a dwelling’s predicted usage does not exceed the legal limit, typically 125 litres.

For every newly created dwelling you must submit a water efficiency calculation report to Building Control for approval.  Getting this correct at the start of a project avoids delays with sign off and any issues with compliance.

Award Energy can complete compliant calculations for you quickly after receiving details of all proposed sanitaryware fittings (including kitchen and utility taps).   If a specification has not been finalised, we can also produce calculations with anticipated flow rates and capacities in order for you to put together your sanitaryware choices.

To check your sanitaryware meets the requirements of Approved Document G, please get in touch at the design stage so that we can keep you on the right track.