Water Efficiency Calculations

Satisfy Part G of the Building Regulations

Can you satisfy Part G of the building regulations with a water efficiency calculation? Look no further! Give us a call, and we'll take care of it for a fixed low-cost fee of just £30.00. You can expect a quick turnaround within 24 hours, often as quickly as the same day.

What is Part G?

New homes, including conversions, must use less than 125 litres of water per person per day, in accordance with Approved Document Part G of the Building Regulations. To show compliance, a water efficiency calculation must be provided to Building Control during the design stage and upon completion of the build.

In addition to these national requirements, local planning authorities can also require an even lower water consumption rate of 105 litres per person per day as part of their sustainability rules. This is often a condition for development approval.

How is water efficiency calculated?

The estimated water usage for a property is determined using the methodology outlined in the Government’s publication “The Water Efficiency Calculator for New Dwellings.”

This calculation takes into account factors such as the capacity of installed baths, flow rates of installed taps and showers, water consumption of any installed washing machines or dishwashers and the flush capacity of all installed toilet cisterns to name a few.