a self-builder’s guide to water effiCienCy

this by adopting a planning condition that follows through to the Building Regulation requirement G1. This means that you will need to submit your water efficiency design as part of the planning conditions discharge process as well.

The Scottish Standards Requirement 3.27 also limits water use for certain appliances, but it is not as comprehensive as Part G.

How to Comply

The easiest way to comply with either standard is to follow the Maximum Fittings Method Table (see overleaf). It sets out a maximum water consumption figure for each appliance, depending on whether you need to meet the 125 or 110 l/p/d standard. However, the table is not always suitable. In projects where you want the freedom to create a bespoke design for your home or where any of the following apply, you should use the design-based water calculation method: l You have one or more appliances or fittings that exceed the limit shown in the fittings table l You are installing a rainwater harvesting system l You are installing a water softener

Shower Bath Basin taps Sink taps Dishwasher

6/4 litres dual flush or 4.5 litres single flush

10 litres/min

185 litres

6 litres/min

8 litres/min

1.25 litres/place setting

8 litres/min

170 litres

5 litres/min

6 litres/min

1.25 litres/place setting