Operational energy & carbon
Assessment & whole life carbon
- BREEAM Credit Estimator CalculatorEstimate the BREEAM rating a building is likely to reach.
- BREEAM Insulation CalculatorCheck pipe insulation against what a BREEAM assessment expects.
- Embodied Carbon Quick EstimatorBuild a quick embodied carbon figure from your material list.
- Whole-Life Carbon (A1-C4) CalculatorAdd up a building's carbon from construction to demolition.
Low carbon options & payback
- Carbon Payback CalculatorSee how long carbon savings take to repay the carbon spent.
- Heat Pump vs Gas (SCOP) CalculatorCompare running cost and carbon of a heat pump against gas.
- Lifecycle Cost / NPV / Payback CalculatorAppraise an investment over its whole life, not just up front.
- Solar PV Generation & Savings CalculatorEstimate what a rooftop solar array will generate and save.
About these sustainability calculators
The sustainability set covers the carbon numbers a project is now routinely asked for: what the building emits in use, what was emitted making and installing it, and whether a proposed measure pays back in carbon terms.
Operational carbon uses the UK Government GHG Conversion Factors published by DESNZ, with benchmarks from CIBSE TM46 and reporting aligned to CIBSE TM41. Embodied and whole life carbon follow the RICS Whole Life Carbon Assessment stage structure and BS EN 15978 - upfront carbon as A1-A3 plus A4 and A5, use stage as B1-B7, with whole life as A + B + C. Solar PV yield uses MCS MIS 3002 and IEC 61724-1 performance ratio methodology. The BREEAM estimator works to the current credit structure.
They are aimed at contractors and designers responding to carbon requirements in tenders and planning conditions, who need a credible figure without commissioning a full assessment.
Treat them as scoping tools. They will tell you the order of magnitude and where the carbon sits, which is usually enough to steer a decision - but a formal RICS assessment or BREEAM submission needs the full method and an assessor.
Frequently asked questions
Which carbon factors do these use?
The UK Government GHG Conversion Factors for Company Reporting published by DESNZ. Grid electricity factors change annually, so check the year stated on the page matches the year your assessment is being reported against.
What is the difference between upfront, embodied and whole life carbon?
Upfront carbon is modules A1-A5 - product manufacture, transport to site and installation. Embodied carbon adds the in-use and end-of-life modules other than operational energy. Whole life carbon is everything, A + B + C, including operational energy in B6. The calculators keep the modules separate so you can report against whichever scope is required.
Can I use these for a BREEAM submission?
No. The BREEAM estimator indicates which credits are likely achievable and where the gaps are, which is useful early. A submission must be prepared and evidenced through a licensed BREEAM assessor.