Estimates a building's likely BREEAM rating from the credits achieved in each environmental section, weighted by the BRE UK New Construction 2018 method, overall % = Σ(section % × weighting) + innovation.
Tender-stage indicative only. It omits the mandatory minimum standards, so it is not a certified rating.
For indicative estimating only. Always verify with a licensed BREEAM assessor.
About this BREEAM credit estimator
This free BREEAM credit estimator gives a quick, tender-stage estimate of a building's likely BREEAM rating from the proportion of credits achieved in each of the nine environmental sections, weighted by the BRE method. It is aimed at UK design teams, sustainability consultants and contractors who want an early read on whether a scheme is tracking towards Good, Very Good, Excellent or Outstanding before a licensed assessor is engaged. Enter the percentage of credits expected in each section and, if your scope differs from the standard, adjust the section weightings, the defaults follow the verified BRE UK New Construction 2018 fully fitted-out set, which sums to 100.
How the BREEAM score is calculated
The method follows the BRE BREEAM UK New Construction 2018 (v6) scoring model. Each section contributes its environmental weighting scaled by how much of it is achieved, so the base score is the sum over the nine sections of (section credits % ÷ 100) × section weighting %. The fully fitted-out weightings are Management 11, Health & Wellbeing 14, Energy 16, Transport 10, Water 7, Materials 15, Waste 6, Land Use & Ecology 13 and Pollution 8. Innovation adds up to ten further percentage points, one per innovation credit. The overall percentage then maps to a band: Pass ≥ 30, Good ≥ 45, Very Good ≥ 55, Excellent ≥ 70 and Outstanding ≥ 85, with anything below 30 unclassified. The rating is banded on the raw, unrounded score against the published BRE benchmarks.
Frequently asked questions
Is this the same as a certified BREEAM rating?
No. This is an indicative weighted-score estimate for early decision-making. Certified BREEAM also enforces mandatory minimum standards. Specific credits that must be achieved for each rating band, so a high weighted percentage can still be capped to a lower certified rating in practice. Only a licensed BREEAM assessor can confirm an actual rating.
Why should my section weightings sum to 100?
The standard BREEAM environmental weightings are normalised to total 100 %, so the overall score reads directly as a percentage. The calculator flags any total other than 100 in case you are deliberately modelling a partial or shell-only scope, where the published weightings differ.
What do the rating bands mean?
BREEAM bands an overall score as Pass (≥ 30 %), Good (≥ 45 %), Very Good (≥ 55 %), Excellent (≥ 70 %) and Outstanding (≥ 85 %). Most new UK developments target Very Good or Excellent; Outstanding is reserved for exemplary, sector-leading performance.