What Are Water Efficiency Calculations?
Water Efficiency Calculations measure the estimated water consumption of a new residential development, ensuring compliance with Part G of the UK Building Regulations. These calculations determine whether a building meets the required water usage limits per person per day.
Why Are Water Efficiency Calculations Important?
- Regulatory Compliance – Required for all new dwellings under Building Regulations Part G (Requirement G2).
- Sustainability Goals – Helps conserve water resources and reduce environmental impact.
- Cost Savings – Lower water usage means reduced utility bills for occupants.
Water Efficiency Targets:
- Standard Requirement: ≤ 125 litres per person per day (L/p/d).
- Tighter Target (Optional in Some Areas): ≤ 110 L/p/d (as required by some local authorities).
Key Factors in Water Efficiency Calculations:
- Flow Rates of Taps & Showers – Measures water usage from kitchen and bathroom taps.
- Toilet Flush Volume – Assesses how much water is used per flush (dual flush systems are preferred).
- Bath & Shower Usage – Calculates the typical water consumption per use.
- Dishwashers & Washing Machines – Uses standard consumption values if installed.
- Greywater & Rainwater Harvesting – Accounts for any water-saving technologies.
How Are Water Efficiency Calculations Conducted?
A calculation is carried out using Government-approved methodology, based on installed fittings. If the building meets the target, it can proceed; otherwise, water-saving measures may need to be added, such as:
✅ Low-flow taps and showers
✅ Dual-flush toilets
✅ Water-efficient dishwashers/washing machines
✅ Greywater or rainwater harvesting systems
Would you like help optimizing water efficiency for a specific project? Get in touch for a personalized quote.