Water Calculations - Internal Water Use

Energy Calculations Limited can advise on all water efficiency aspects from the design stage to the as built stage producing a Water Calculation Report for your dwelling enabling you to attain the required assessment criteria set out by Building Regulations.

Water calculations are required by Part G Building Regulations and/or Code for Sustainable Homes to show water efficiency for new dwellings.

The calculation is produced based on factors such as occupancy, appliances, water efficient fittings and flow rates. Credits can be gained for meeting assessment criteria by introducing flow restrictors, low flow shower heads and low flush toilets.

Building Regulations state you must meet the required criteria of 125 litres per person per day for domestic dwellings. This is broken down by internal water use of 120 litres per person per day and an allowance of 5 litres per person per day for outdoor water use. This is in line with Code Levels 1 and 2.

Certain Local Authorities will require a reduction in the minimum 125 litres per person per day as part of their local planning policy.

Code for Sustainable Homes was introduced by the Government to improve the environmental specification of new homes. Credits are awarded for achieving set standards in different aspects of development. Water consumption inside a dwelling is one of the compulsory aspects to achieve and a total of 5 credits are available for water consumption.

Water consumption specifications for Code levels are as follows:-

  • Level 0 - Part G of the Building Regulations
  • Levels 1-2 - less than 120 litres/person/day - credits awarded 1-2
  • Levels 3-4 - less than 105 litres/person/day - credits awarded 3-4
  • Levels 5-6 - less than 80 litres/person/day - credits awarded 5

We offer a cost effective solution to the internal water calculations, design stage with a check list/sign off for the developer and a post completion stage certificate.

Please do not hesitate to contact us should you require advice or assistance.

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