Water Efficiency Calculations

What Are Water Efficiency Calculations?

Water efficiency calculations assess the estimated daily water consumption of a property based on its installed fittings and systems. Using government-approved methodology and the Part G water calculator, we measure how much water occupants are expected to use.

The calculation considers:

Taps and flow rates
Toilets and flush capacities
Showers and flow rates
Baths and capacity
Dishwashers and washing machines
Any rainwater or greywater systems

Once the assessment is complete, you receive a Water Efficiency Certificate to present to Building Control.

Matters

Why Water Efficiency Matters

The UK faces increasing pressure on water resources, and new homes must be designed to use water responsibly. Meeting Part G requirements ensures:

Compliance with Building Regulations
Reduced water bills for future occupants
More sustainable construction practices
Improved environmental performance

In some regions, local authorities impose stricter limits — often 110 litres per person per day — which we can help you achieve with tailored solutions.

Why Choose

Why Choose Home Energy EPC for Water Efficiency Calculations?

We work closely with builders and designers to provide fast, clear and reliable calculations that keep your build compliant.

What Makes Our Service Stand Out:

Fast turnaround times (usually within 24 hours)
Fully compliant with Part G requirements
Simple submission process — just send your specifications
Clear digital certificate for Building Control
Free advice on how to pass if you fall short
Combined packages with SAP EPC, BREL, Air Tests and Ventilation Tests

Whether you are building one home or a multi-plot development, we provide accurate and supportive compliance guidance.

What’s Included

What’s Included in Water Efficiency Calculations?

Our assessment covers every relevant water-using fixture and appliance in the property.

Review of All Sanitaryware

We assess taps, showers, baths, toilets and kitchen fixtures.

Flow Rate and Capacity Verification

We confirm flow rates and volumes from manufacturer data or site specifications.

Greywater or Rainwater System Inclusion

If your project includes water recycling measures, these are integrated into the calculation.

Full Water Efficiency Assessment

We calculate total predicted daily water use per person.

Certificate Issued

You receive a complete Water Efficiency Certificate for Building Control.

If the calculated figure exceeds the allowed limit, we will advise you on cost-effective improvements.

Who Needs

Who Needs Water Efficiency Calculations?

A Water Efficiency Calculation is required for:

All new-build residential dwellings
Conversions that create new dwellings
New-build extensions assessed under Part G
Any project requiring SAP assessments

If you’re building a home or converting a property into flats, this calculation is essential.

Take

How Long Does the Assessment Take?

Once we receive your specifications, calculations are typically completed within 24 hours. For urgent projects, we offer same-day turnaround.

Common Reasons

Common Reasons for Failing Water Efficiency Targets

Most failures are caused by:

High-flow showers
Oversized baths
Dual-flush toilets with incorrect ratios
Taps with high flow rates

We provide simple recommendations such as aerated taps or water-saving shower heads to help you meet compliance.

Offer

Pricing

Our pricing is competitive and straightforward. Discounts are available for multi-plot developments and combined service bundles.

let’s make it shine!

Book Your Water Efficiency Calculations Today

Home Energy EPC offers fast, accurate and fully compliant Water Efficiency Calculations to keep your project on track for Building Regulation approval.

info@homeenergyeepc.co.uk

0121 000 0000

Book your assessment today and ensure your new build meets all Part G water-use standards.