Turn a fixture schedule into a coordinated calculation
Water efficiency depends on the specified outlets and appliances, so a schedule of the actual products is a useful starting point. Include the information supplied by manufacturers rather than assuming that products with similar descriptions have the same consumption. Tell us if the project has a particular planning condition or water target.
What the assessment covers
A water efficiency calculation brings together the specified taps, showers, baths, WCs and appliances. Review fixture choices and prepare supporting calculations for the project’s water efficiency requirements.
Useful starting information: sanitaryware schedules, flow rates, flush volumes, appliance specifications and any planning water target.
Part G guidance — England ↗Keep product substitutions in view
Changes to showers, taps, WCs and appliances can alter the calculation. Mark revised items clearly and provide their new specifications before treating the original assessment as representative of the final scheme. If products have not been chosen, identify the open decisions so the initial scope and later updates can be agreed.
Your questions
Which product information is useful?
Send tap and shower flow rates, WC flush volumes, bath capacities and the water-consumption data available for specified appliances.
Is this the same as hot water sizing?
No. A water efficiency calculation reviews predicted consumption; a hot water load calculation supports decisions about generation and storage capacity.
Building regulations and assessment routes differ across the UK. Project location, the applicable requirements and deliverables are confirmed when agreeing the scope.