Accredited assessors
UK-wide coverage
Established in 2012
HELPING YOU STAY PART G COMPLIANT
Expert Energy Consultancy Ltd specialises in accurate, efficient water usage calculations for new dwellings and conversions across the UK. Part G of the Building Regulations requires that water use is limited to 125 litres (or 110 litres under local policy) per person, per day. We assess your fixtures, fittings, and appliances to ensure compliance before and after construction.
Whether you're an architect, builder, or homeowner, we guide you from design to as-built documentation.
Contact us today to speak with our experienced consultants and request your water efficiency report.
What is a Part G water usage calculation?
Part G calculations assess the predicted daily water consumption of a residential property. They’re based on the flow rates and capacities of all sanitary fittings, such as taps, showers, baths, and toilets, as well as kitchen appliances and water-saving technologies like aerated taps or rainwater harvesting systems. The goal is to ensure the projected usage doesn’t exceed regulatory limits. We provide detailed assessments aligned with the latest building standards to help you stay compliant and avoid costly delays in the approval process.
When do you need a Part G water efficiency calculation?
Water usage calculations are mandatory at the design stage of all new residential builds. You’ll also need them for conversions such as office-to-flat changes or other residential adaptations. Local authorities enforce a lower water limit of 110 litres in some areas. Your calculation must be updated with as-built figures once construction is complete. If Building Control or your planning department requests it, we’ll provide everything you need for sign-off.
Our water usage calculation service includes:
We deliver a complete, professional service for Part G compliance. This includes a design-stage report based on your plumbing specs, fixture list, and an as-built update using actual installation details. If your planned specification exceeds the water limit, we will recommend practical adjustments to bring it into line.
You’ll receive a ready-to-submit PDF report accepted by Building Control and Approved Inspectors. Whether it’s a single home or a complete development, we help you build smarter, more efficient spaces.
