Standards reconsiders water use
AECB (formerly the Association for Environment Conscious Building) has published a water standard that is applicable to new homes, the refurbishment of existing dwellings and non-domestic buildings.
This water standard is aimed at specifiers, architects and house builders. It has two levels (good and best practice) and a third experimental category.
The standard prioritises reductions in the most environmentally damaging uses of water.
One is hot water, which accounts for almost 90% of the carbon footprint of all domestic water.
The other is the use of water in times and places of drought stress — addressing peak summer demand and demand in drought-stress locations.
AECB does not give credits for systems, since the energy and carbon costs of pumping and treating rain and grey water often exceed the carbon cost of mains water. The standard also encourages good plumbing design to reduce the waste of energy.