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Water Efficiency Calculations

Why you need a Water Efficiency Calculation

 

It is a requirement of the Building Regulations: Part G that a whole building water Efficiency standard of 125 litres per person per day for new build and converted dwellings is not exceeded. This comprises internal water use of 120 litres per person per day, and an allowance of 5 litres per person per day for outdoor water use.

 

The maximum of 125 litres per person per day must be specified using the methodology set out in the Building Regulations Part G: Water Efficiency Calculator for New Dwellings.

Building Control requires that a Water Efficiency Calculation is provided to demonstrate that the proposed dwelling will function with a water level consumption of less than the 125 litres per person per day target.

 

SAP / EPC is aligned to the Building Regulation requirements and a water efficiency calculation is required for the SAP calculation.

 

How is a Water Efficiency Calculation worked out

 

The calculation is based on the water appliances and fittings of the property to calculate the overall consumption per person per day and in order to comply with these regulations, careful consideration must be given to the sanitary ware, plumbing fittings and general white goods being installed for flow rates and volumes for water usage when calculation the overall water consumption.

 

Chiltern PSC Water Efficiency Calculation

 

Is a bespoke calculation based on the ‘Water Efficiency Calculator for New Dwellings’ and follows the Governments national assessment methodology which enables us to provide clear information for you and Building Control.

 

The Water Efficiency Report will contain:

  • Water Efficiency Calculation

  • Summary page with corresponding products and flow / capacity rates

  • Separate “Design” (including Builders check list) and “As Built” Reports

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