Part G water efficiency calculation factors v1.0 · 22 Aug 2026
The complete Table 1 of The Water Efficiency Calculator for New Dwellings (DCLG, 2009) — the methodology required by Approved Document G and Building Regulation 36 — plus the 0.91 normalisation factor, the fixed 5 l/p/d external-use allowance, the unspecified-appliance defaults and the multiple-fittings averaging rule. These are the exact constants WaterMonkey calculates with, cross-checked against the published document.
Prefer it explained? The factors are worked through fitting by fitting in the no-spreadsheet guide, with a full worked example from fittings schedule to final figure.
England nutrient-neutrality catchments v1.0 · 2 Sep 2026
All 27 nutrient-neutrality catchments in England: the protected site each one serves, whether it is assessed for nitrogen or phosphorus (or both), the counties it reaches, and the official credit price where a scheme publishes one — 10 of the 27 do. Plus the constants every nutrient budget uses: Natural England's 2.4 persons-per-dwelling default, the +10 l/p/d water-use allowance and the 20% precautionary buffer. Prices and catchment boundaries both move, so every row carries the scheme name and its caveats alongside the number — and an empty price means not published, never zero.
Every row carries a link to that catchment's page, where the free nutrient neutrality calculator runs the budget for you — occupancy, water use, concentrations and the 20% buffer.
Licence & citation
Everything on this page is published under CC BY 4.0 — free to reuse, including commercially, with attribution to energycount.co.uk. The underlying figures are Crown-published methodology values and public-body designations; the licence covers our verified machine-readable arrangement of them. Suggested citation:
Energycount (2026). UK building-compliance open data (v1.0). https://energycount.co.uk/data/ — accessed [date].
Spotted an error, or want another compliance dataset published (Part L limiting U-values, SAP default Ψ-values, BRE 365 storm data)? Tell us — this page will grow.