Improving Water Efficiency

How we are addressing this issue:

Given the widely accepted prediction that, over time, water shortages will become common in the UK due to increasing demand and hotter, drier summers, we see the minimisation of water use in our new homes as very important and are committed to designing our homes to use less. We can reduce the demand for fresh water within the dwellings we build by providing reduced-flow sanitary ware, or installing water re-use devices such as greywater harvesting and recycling.

All of our developments include measures to reduce water consumption as part of our commitment to the Code for Sustainable Homes. The average consumption of water in the Code-certified homes we build is currently 100 litres per person per day, far below the UK average of 150 litres per person per day. This equates to a reduction in metered water bills of approximately £168 per household, per year¹.

As we continuously seek to of improve the water efficiency of the homes that we build, we devote time to talking to and engaging with our suppliers to find innovative fixtures and fittings that save water and are of the high standard expected in a Berkeley home.

"Waterwise has worked with Berkeley to help inform [the] 'Let's Talk' Water Conference and Water Routemap both of which are excellent tools to help disseminate knowledge on reducing water use...The Berkeley Group is one of the leading developers in terms of their understanding and approach to water efficiency...Waterwise is delighted that developers like Berkeley are working so hard to produce properties to the highest environmental standards without compromising on luxury or design. And even more than that they are also giving clients helpful advice on lifestyle changes that can help save the environment without compromising their standard of living."

Jacob Tompkins, Waterwise

Our performance:

In 2010/11:

• The average consumption of water in the Code-certified homes we built was 100l/p/d.
• 100% of homes submitted for planning committed to achieving a water use of 105l/p/d (with the exception of those sites listed here) in order to gain Code Level 3 certification.

Our Vision2020 commitments and ambitions:

As part of delivering Vision2020 we have set specific objectives for continuing to ensure that we increase water efficiency in the developments we build.

Our commitment from May 2011:

• Design all new homes to achieve water use of 105l/p/d (a 30% reduction compared to average home water use)

Our ambition from May 2012:

• Implement rainwater harvesting on all high-density schemes

Case studies:

Rainwater harvesting at Grosvenor Waterside

At Grosvenor Waterside, a mixed-use development in Chelsea, we have installed water meters for every homes, provided water efficient appliances and installed a site-wide rainwater harvesting system. Whilst the intention is for the harvested water to be used to irrigate the site's landscaping, it was installed early on in the development process and is currently being used in the construction site welfare accommodation to minimise water consumption during construction.

Testing water regulations at West 3

Restrictions on indoor water consumption are new to the house building industry and will have a tangible impact on how a purchaser lives in their home. There is therefore a need to establish:

• What fixtures are available to the industry to help achieve the performance standards set in the Code and how they perform
• How the Code performance standards impact on actual, and not just theoretical, water usage in new homes
• Customer perceptions about the restrictions on indoor water use and how these may impact on the market for new homes in the future

In order to assess this on a practical level, we used a completed two bedroom, two bathroom apartment unit at our West 3 development in Acton to test the implications of each of the mandatory performance requirements set by the Code. The study ran over a period of five, month long intervals during which the fixtures in the unit were changed to meet the water use performance standards of the Code. Two occupants lived in the unit during the study period and water use was monitored via a data logger fitted to the water meter. The occupants were surveyed at the end of each month long period to establish their perceptions of the various specifications.

Surprisingly, the results of our research show that average monthly water use in the unit over the trial period remained within the range 55-61 litres per person per day, and did not display a progressive pattern of reduction at the higher standards. This could be explained by our sample residents using the taps/shower for longer when flow rate is reduced. Results also indicate that where flow rates are too low, customers may consider replacing them to gain better performance. The findings of this research will be incorporated into future practice.

¹ Based on an average household of 4 people and a reduction in water consumption from 150l/p/d to 100l/p/d. Assuming that on average, a litre of tap water, supplied and taken away, costs 0.23p (see Ofwat).