We provide precise and professional Part G Water Efficiency Calculations to help ensure your development meets the requirements set out in the Building Regulations. Under Part G, new dwellings must demonstrate that water consumption does not exceed 125 litres per person per day, including both internal water use and an allowance for outdoor consumption.

Going Beyond Compliance

While 125 litres/person/day is the legal maximum, many projects aim for significantly lower figures to meet stricter sustainability targets, planning conditions, or accreditations such as:

• Passivhaus: Although not directly tied to water consumption, Passivhaus principles align with low-resource, high-efficiency living. Reducing water usage supports overall environmental performance.

• BREEAM & Code for Sustainable Homes (legacy): These systems often require consumption as low as 105 litres/person/day or less to achieve higher ratings.

• Local planning policy: Some councils and planning authorities impose tighter limits (e.g., 110 l/p/d) as part of sustainable development targets.

• Net Zero and eco-home schemes: Water efficiency plays a growing role in whole-house performance strategies.

How We Help

We work with developers, architects, and self-builders to optimise water use without compromising comfort or functionality. By advising on low-flow fixtures, aerated taps, water-efficient appliances, and smart irrigation methods, we help you go beyond basic compliance and unlock sustainability credits or meet enhanced planning conditions.

Whether you’re building to regulation, aiming for Passivhaus, or preparing for a low-carbon future, we can support your project every step of the way.