Solutions
The following pages explain a number of technologies and design principles that reduce potable water consumption and minimise flood risk. A summary of water saving options is presented in the table below.
In most cases, solutions are applicable to all types of development and both new projects and refurbishments.
However, some solutions such as rainwater harvesting or certain sustainable drainage techniques are only applicable to particular types of location or development. For example, rainwater harvesting is more suitable to buildings that have a large roof area.
Much of the information in this section is sourced from the Environment Agency's research Conserving Water Use in Buildings.
Further information and current news on water saving devices is available from environment-agency.gov.uk/homeandleisure/drought/default.aspx
Example water efficiency costs and savings
| Solution | Cost/Unit | Typical Savings (%) | Savings* (Litres) |
|---|---|---|---|
| Low flow taps | £ | 60% compared to regular taps | 33 per person per day (based on 30% of water use for taps) |
| Urinals with flow control | £ | 50% compared with regular flush urinals | 5 per bowl per hour |
| Waterless urinals | £ | 100% | 10 per bowl per hour |
| Dual/low flush toilets | 0-£ | 20-50% | 3-6 per flush |
| Low flow showers | 0 | 50% compared to regular showers | 30 per use |
| Rainwater harvesting | £-££** | 30% of household water use | 55 per person per day |
| Greywater recycling | £££ | 30% of household water use | 55 per person per day |
Key
* Based on Hertfordshire average consumption rate of 182 litres per person per day (66.43m3/year)
** Variation in cost dependant on nature of harvesting product, i.e. rainwater butt = low cost, basement rainwater harvesting tanks + additional pipework = medium cost
0 = no additional cost £ = low cost ££ = medium cost £££ = relatively high cost