Start Your Calculation Choose your project's maximum potable water consumption. Performance Target Litres / Person / Day Compliance England Building Regulations 125 120 litres per person per day 120 110 litres per person per day 110 105 litres per person per day * 105 80 litres per person per day * 80 Your own defined level * There may be incentives – check with your project's local Water Utility. Enter a name to help you identify this project. Project name The performance target and project name can be changed later. Cookies and JavaScript must be enabled in your web browser.Once you have finished, you can print your results and/or save them to our database. Terms and Conditions of Use