Whole Life Carbon Assessment

What is whole life carbon?

Whole life carbon (WLC) is the total greenhouse gas emissions associated with a building across its entire lifecycle - from extracting raw materials and manufacturing products, through construction, operation, maintenance, and eventual demolition or deconstruction. It is measured in kilograms of carbon dioxide equivalent (kg CO2e).

Whole life carbon assessment (WLCA) is the process of calculating this total. It combines two major components: embodied carbon (the emissions from materials and construction) and operational carbon (the emissions from energy used to heat, cool, light, and power the building during its life).

This is distinct from measuring embodied carbon alone, which only captures part of the picture. A building with very low embodied carbon but poor operational efficiency could have higher whole life carbon than one with slightly higher embodied carbon but excellent energy performance. WLCA captures both.

Lifecycle stages (EN 15978)

WLCA follows the lifecycle stages defined in BS EN 15978, the European standard for assessing the environmental performance of buildings. Understanding these stages is essential for interpreting and comparing WLC assessments.

Lifecycle stages - A1 to D

1
A1–A3
Product stage
2
A4–A5
Construction
3
B1–B7
Use stage
4
C1–C4
End of life
5
D
Beyond lifecycle

Watch out. When comparing WLC figures between projects, always check which modules are included. An assessment covering A1-A5 only is NOT a whole life carbon assessment - it is an upfront embodied carbon assessment. True WLCA includes A-C modules, with D reported separately.

Why WLCA matters now

Whole life carbon assessment is moving from best practice to regulatory requirement in the UK and across Europe. Several factors are driving this shift.

Topic	Detail
GLA requirement	the Greater London Authority requires WLCA for all major planning applications (referable schemes). This has normalised the practice for large London projects since 2021
RICS Professional Statement	the RICS Whole Life Carbon Assessment standard (2nd edition, 2023) provides a consistent methodology and is increasingly referenced in planning policy
Part Z campaign	the proposed Part Z amendment to Building Regulations would make embodied carbon reporting (and potentially limits) a legal requirement for new buildings in England
RIBA 2030 Climate Challenge	sets embodied and operational carbon targets that require WLCA to measure progress
LETI guidance	the London Energy Transformation Initiative publishes benchmarks for embodied carbon by building type that are widely used as targets
EU Level(s) framework	the European Commission's Level(s) framework includes WLC as a core indicator, signalling future pan-European regulation
Client demand	institutional investors, corporate occupiers, and public bodies are increasingly requiring WLCA as part of project brief and ESG reporting

How to conduct a WLCA

A whole life carbon assessment follows a structured process, ideally starting at RIBA Stage 2 and refined through each subsequent design stage.

Topic	Detail
Define the scope	reference study period (typically 60 years for UK buildings), modules to be included (minimum A1-C4, with D reported separately), and system boundary (which building elements are included)
Gather quantity data	from the design model, cost plan, or specifications. At early stages, use area-based benchmarks and elemental estimates. At later stages, use measured quantities from the BIM model or bill of quantities
Source carbon data	use product-specific EPDs where available. For products without EPDs, use generic datasets (ICE Database, RICS database, or national databases). Note which data is product-specific vs generic
Calculate embodied carbon (A-C)	multiply material quantities by carbon factors. Include construction waste, transport, replacement cycles, and end-of-life processing
Calculate operational carbon (B6-B7)	from energy modelling (Part L calculations, PHPP, or dynamic simulation) combined with carbon intensity factors for electricity and gas over the study period
Report	follow RICS Professional Statement format. Report each lifecycle module separately, state data sources, and flag data quality. Include a comparison against relevant benchmarks (LETI, RIBA 2030)

Tip. Tools like One Click LCA, eTool, and FCBS Carbon make WLCA calculation more efficient. Several integrate directly with BIM models. At early design stages, the RIBA/LETI embodied carbon calculators provide a simpler starting point.

How WLCA informs material choices

WLCA reveals which material decisions have the greatest impact on a building's total carbon footprint and allows like-for-like comparison of alternatives.

Topic	Detail
Structural frame comparison	WLCA quantifies the carbon difference between concrete, steel, and timber frames - typically the single largest material decision. Including module B (replacement) and C (end of life) can change the ranking compared to A1-A5 alone
Replacement cycles matter	a floor finish with low A1-A3 carbon but a 10-year replacement cycle may have higher B4 (replacement) carbon over 60 years than a more durable option with higher upfront carbon
Operational vs embodied trade-offs	WLCA reveals whether investing in higher-embodied-carbon insulation (e.g. vacuum insulated panels) is justified by the operational energy savings it delivers over the study period
End-of-life matters	materials that can be recycled (steel, aluminium) or composted (timber, hemp) show benefits in module C and D that are invisible in an A1-A5 only assessment
Data quality signals	WLCA forces you to confront data quality. Products with EPDs provide reliable data; those without require conservative generic values that may overstate their impact

Using Matera for WLCA

Matera helps you source the product-specific environmental data that underpins credible whole life carbon assessment. Filter products by EPD availability, compare embodied carbon figures between alternatives, and use verified data to improve the accuracy and credibility of your WLCA.