UK’s first eco town
Ninety-one zero-carbon homes in Oxfordshire have been fitted with complete rainwater harvesting and stormwater management systems from Graf UK – helping them achieve Code for Sustainable Homes Level Five standards and minimise flood risk.
The homes are the first to be built in the UK’s first eco town, North West (NW) Bicester, as part of the Elmsbrook phase of the project. All the homes will be fitted with extensive efficiency measures, such as solar PV panels and triple glazing. To reach Code for Sustainable Homes Level Five standards, the developers needed to limit each property’s potable water consumption to just 80 litres per person, per day. As well as reducing pressure on the mains supply, flooding protection was also a key concern – so civil engineering consultancy, Infrastruct CS Ltd, specified a water management solution.
The Infrastruct team worked with Graf UK to design, install and commission a complete rainwater harvesting and stormwater management package for each of the properties – consisting of a 1,500L Platin tank and a soakaway made of Rain Bloc modules.
Tim Trotman, Director at Infrastruct, explains: “The Platin tanks sit underground, and use submersible pumps to feed collected rainwater into a header tank in the loft of each home. The header tanks then gravity-feed the water to the properties’ bathrooms, where it is re-used for sustainable toilet flushing.
“The system is engineered to use hardly any mains water, only diverting to the mains supply if the tank is empty (for example, after a particularly hot, dry spell). This not only helps save water, but also keeps bills down for homeowners and tenants. To manage excess water in the event of heavy rainfall, each rainwater harvesting system has its own soakaway made up of Graf’s Rain Bloc modules. These stormwater tanks all feed into a central soakaway, where water is gradually released back into the underlying ground conditions in a controlled way – reducing pressure on the drains and minimising flood risk.”