Tougher Water Efficiency Standards Continue to Expand in England

Planning authorities in southern England are increasingly seeking to adopt more onerous water efficiency standards. New developments in such locations should first prioritise achieving this with practical and cost-effective solutions, such as flow restriction devices, efficient white goods, and encouragement of behavioural changes. Homes can achieve 85 l/p/day on average from such measures.

Reductions beyond this are likely to require grey and/or rainwater recycling systems. These can deliver significant further savings, however present more complex, costly, and often carbon-intensive methods. These systems come with the following complications:

• Space & complexity – additional/larger risers, plant rooms, and configuration of multiple plumbing routes to/from outlets
• Material – a large increase in the volume of pipework, tanks, BMS integration, and associated chemical/bacterial agents for dosing
• Energy & carbon emissions – water is very dense, meaning it requires a lot of energy to pump around buildings. Doing this for rain and greywater as well as potable water will increase energy demands and thus carbon emissions
• Cost – capital costs can be high, as well as operational costs associated with ongoing maintenance activities and increased energy demands
• Odour/visuals (greywater)– end-users must be content to use discoloured water, with potential odour ramifications, for flushing toilets

In addition to the ongoing water neutrality requirements in the Sussex and Cambridge areas, some London Boroughs are also looking to adopt stricter requirements. Policy CG8 of Tower Hamlet’s Reg. 19 Local Plan, for instance, includes a target of 80l/p/day and a requirement to install rain and greywater recycling systems.