Whole-life carbon (WLC) refers to the combined total of embodied and operational emissions over the whole life-cycle of a building. In practice, a WLCA quantifies the entire amount of carbon produced by a built asset throughout its life cycle, comprised of both operational and embodied carbon. In other words, WLCA accounts for carbon from manufacturing every beam and brick (embodied emissions), through building use and maintenance (operational emissions), right up to demolition and disposal (end-of-life) of the building parts. By summing these stages, WLCA provides a true picture of a building’s total carbon impact.
This holistic approach differs from a conventional operational carbon focus. Traditionally, the industry focused on cutting energy use and heating emissions (operational carbon) while overlooking the embodied carbon in materials and construction. WLCA fills that gap by considering both. As RICS guidance notes, it prevents counterproductive decisions, for example, adding carbon-intensive materials to save a smaller amount of energy can backfire if only operational savings were considered.
In short, WLCA equals embodied carbon and operational carbon combined, measured over a building’s full life-cycle.
Governments and clients are increasingly requiring WLCA to drive down emissions. London already mandates Whole Life-Cycle Carbon Assessments for all major developments at the planning stage. A proposed amendment to UK Building Regulations, Part Z, would make WLCA reporting compulsory nationwide. While Part Z isn’t law yet, its direction is clear — prepare for embodied carbon limits and disclosure. Major industry bodies (RIBA, RICS, LETI, UKGBC) have aligned on the urgency of WLCA to achieve net-zero goals. For product manufacturers, this means their materials’ carbon footprints now directly influence building compliance and procurement choices.
A life-cycle assessment (LCA) is a broad methodology, standardised by ISO 14040/44, to evaluate multiple environmental impacts of a product or system from “cradle to grave.” WLCA is essentially a carbon-focused LCA of a whole building. The scope of WLCA is defined by standards like BS EN 15978 (for buildings) and the RICS Professional Statement on WLCA. These frameworks break the building life-cycle into modules A (production/construction), B (use/maintenance), C (end-of-life), plus module D (beyond-life benefits). General LCA might assess various impacts (carbon, water, pollution) for a single product or material, whereas WLCA focuses on greenhouse gas emissions across all building components and stages. In practice, WLCA calculations use global warming potential (CO₂e) as the metric, aggregating data from many product LCAs (i.e. EPDs) to compute a building’s total footprint.
Another difference is operational energy: A product LCA usually doesn’t include use-phase energy, but a WLCA must include operational carbon (heating, cooling, power over the building’s life). This requires integrating building energy modelling with embodied carbon data. WLCA thus demands a broader data set — from material manufacturing impacts to predicted energy use and even end-of-life scenarios. Done right, a WLCA helps project teams balance trade-offs (e.g. materials vs. insulation vs. renewables) for optimal whole-life outcomes.
Conducting a WLCA involves assembling comprehensive data and using robust tools:
Multiple regulatory drivers are making WLCA a mainstream requirement.
The voluntary Part Z proposal would mandate whole-life carbon assessments and set carbon limits for new buildings. While awaiting adoption, momentum grows, the London Plan 2021 already requires WLCA statements for referable projects, with guidance detailing methodology, using RICS and EN 15978, and requiring developers to calculate and reduce WLC emissions. Several local authorities and private developers now expect WLCA as part of design submissions, even where not legally compulsory, as part of their net-zero commitments.
The RICS published a globally applicable Whole Life Carbon Assessment for the Built Environment standard (1st ed. 2017, updated 2nd ed. 2023) to formalise how WLCAs are done. It provides consistent definitions, scope (cradle-to-grave, with modules A–D), and reporting formats. WLCA must be carried out in accordance with BS EN 15978, which is the calculation framework referenced by RICS and others. Additionally, organisations like UK Green Building Council (UKGBC) and LETI have issued guidance and a Net Zero Whole Life Carbon Roadmap, reinforcing industry alignment on WLCA. The UKGBC roadmap makes clear that without tackling whole-life carbon, the built environment will fall short of net-zero by 2050.
In the EU, the Construction Products Regulation (CPR) was revised to require mandatory environmental performance reporting for products. Manufacturers will need to include EPD data in the product’s Declaration of Performance. The upcoming Ecodesign for Sustainable Products Regulation (ESPR) goes further, introducing Digital Product Passports (DPP) to digitally store product sustainability data (including carbon footprint) for all products sold in the EU. These initiatives mean construction products will come with transparent carbon data by default, greatly facilitating WLCAs at building level. For Irish or UK manufacturers exporting to the EU, preparing for DPP and EPD requirements is now critical.
The whole-life carbon trend extends to company obligations. The EU’s Corporate Sustainability Reporting Directive (CSRD) and the UK’s net-zero procurement policies are putting Scope 3 emissions (value chain emissions) in the spotlight. For example, from 2021 the UK government requires suppliers bidding on major contracts to publish a Carbon Reduction Plan including Scope 1, 2 and Scope 3 emissions. This effectively pushes construction firms to quantify emissions from materials and construction processes, which a WLCA helps do, to win public contracts. Meanwhile, private investors and developers are seeking projects with lower embodied carbon to meet ESG goals. Green Public Procurement criteria in the EU (and emerging in the UK) increasingly ask for whole-life carbon data or EPDs at tender stage. All told, tracking and reducing whole-life carbon is fast becoming a business necessity in construction.
Life-cycle assessment (LCA) and environmental product declarations (EPDs) form the bedrock of credible WLCAs. Think of WLCA as building-level carbon accounting, which is only as good as the product-level data feeding into it. This is where EPDs – standardised LCA-based reports for products are crucial.
An EPD provides the carbon impacts and other environmental metrics of a product across specified life stages, typically A1-A3 manufacturing, and often beyond. By supplying transparent, third-party verified data for each material or product, EPDs enable building assessors to sum up embodied carbon with confidence. Without an EPD, assessors must rely on generic industry averages which might penalise a manufacturer’s product even if it is more sustainable than competitors. That’s why manufacturers are investing in streamlined LCA tools to create EPDs for their product ranges. One Click LCA’s EPD Generator is one example of making this feasible at scale. The tool automates the complex LCA calculations and aligns with EN 15804 and ISO standards so that the resulting EPD can be used directly in any WLCA software or database.
From the design side, LCA software aggregates all those EPDs and material quantities to calculate whole-building impacts. Modern tools often include extensive product-specific EPD databases, national and international, so users can simply select the products or input generic options. For instance, One Click LCA’s database hosts hundreds of thousands of EPDs, allowing AEC users to swap materials in their model and instantly see carbon differences. This synergy means that as more manufacturers publish EPDs, design teams can make more informed low-carbon choices — creating a positive feedback loop driving down emissions industry-wide.
In summary, product LCAs and EPDs, and building WLCA are two halves of the whole-life carbon equation. EPDs give manufacturers a way to prove and improve their products’ carbon performance, and they give designers the trustworthy data needed to deliver buildings with lower whole-life carbon. Together, they enable data-driven decision-making, replacing guesswork with numbers. In the era of carbon accounting and transparency, leveraging LCA and EPDs is how companies can meet emerging WLCA mandates and gain a competitive edge by demonstrating genuine carbon reductions.
Not yet at the national level — but it’s heading that way. WLCA is currently mandatory for certain projects in London (per the London Plan) and is strongly encouraged by frameworks like RICS. The proposed Part Z regulation would require WLCA and set carbon limits for all new UK buildings. While Part Z is still under review, many developers and local authorities already require WLCA reports as part of planning or sustainability strategies. Additionally, public sector bids (via PPN 06/21) effectively mandate carbon reporting including supply-chain (embodied) emissions — which a WLCA helps provide. In Ireland and the EU, WLCA is becoming embedded through building regulations (e.g. France’s RE2020, Netherlands’ MPG) and the trend is similar: prepare for WLCA to move from voluntary to required within the next few years. Even where not legally required, doing a WLCA is fast becoming standard practice for demonstrating alignment with net-zero goals.
You will need a combination of data and tools. Key requirements include: a detailed bill of quantities/materials for the building, carbon data for each material (ideally from EPDs or LCA databases), an estimate of operational energy use (for calculating operational carbon), and assumptions for end-of-life (demolition, waste, recycling). A calculation tool or software is essential to manage the life-cycle scope — tools range from spreadsheets following BS EN 15978 formulas to specialised software like One Click LCA, eTool, or Tally. These tools come pre-loaded with LCA datasets and EPD libraries to speed up the work. One Click LCA has the world's largest database of material EPDs and generic datasets.
You’ll also need to follow an established methodology (e.g. RICS WLCA standard or ISO 14044) to ensure the assessment is done correctly. If you’re new to WLCA, it may help to engage a sustainability consultant or use training resources to get started. In short: data (EPDs, quantities, energy), software, standards, and compliance equals a successful WLCA.
WLCA is closely tied to what are known as Scope 3 emissions — the indirect emissions in supply chains. For a building owner, the embodied carbon from construction materials and processes constitutes part of their Scope 3 emissions. For a product manufacturer, emissions from the product’s use and end-of-life are Scope 3. By doing a WLCA of a project, you’re essentially quantifying a big portion of the Scope 3 emissions associated with that project (from raw materials, transport, construction, maintenance, etc.). This is increasingly important in procurement: public and private clients want to purchase low-carbon buildings and materials. The UK government’s procurement rules (PPN 06/21) now explicitly consider suppliers’ Scope 1, 2 and 3 emissions, meaning if you can demonstrate lower whole-life carbon, it can be a market differentiator. In practical terms, a WLCA can inform greener procurement by identifying which materials or design options have lower embodied carbon, allowing tenders to specify carbon limits or require bidders to submit WLCA results. Companies that understand their product’s life-cycle carbon via EPDs, and can optimise it, will have an advantage in bidding for work in this new landscape.
EPDs are third-party verified reports of a product’s environmental impacts, including its carbon footprint per unit (e.g. per m³ of concrete or per kg of steel). In the context of WLCA, EPDs are invaluable: they provide the trustworthy data needed to compare products and make lower-carbon choices. For example, if two insulation materials have EPDs, a designer can see which has, say, 5 kgCO₂e/m² vs 20 kgCO₂e/m² and opt for the greener option, potentially saving tons of CO₂ over the building’s life. On the manufacturer side, creating an EPD often highlights “hotspots” in production where efficiency or alternative raw materials could cut carbon — so the process of making an EPD can spur reductions. EPDs also enable participation in green building projects; increasingly, tenders and certifications (BREEAM, LEED, etc.) reward use of products with EPDs. In short, EPDs allow whole-life carbon to be quantified accurately and transparently, which is the first step to managing and reducing it. Without EPDs, WLCA would rely on generic averages and couldn’t drive performance-based selection of materials. Thus, EPDs are a key tool in the industry’s move toward circular economy principles and lower Scope 3 emissions, providing the data foundation to design-out carbon from the start.
Yes. A number of LCA software platforms have emerged to make WLCA faster and more user-friendly. One example is One Click LCA’s software, which was the first to be RICS-validated for whole-life carbon assessments. One Click LCA comes with built-in compliance templates (for standards like RICS, EN 15978, and local methods like the London Plan), extensive global EPD databases, and automation features — for instance, importing a BIM model or Excel BoQ to auto-calculate impacts. Other similar tools include eToolLCD, Athena Impact Estimator, and Tally, each with their regional strengths. The choice often depends on project size, required reporting format, and user preference. The good news is the right software eliminates much of the tedium — it handles unit conversions, summing across life-cycle stages, and generating the tables and charts needed for reports. When evaluating software, look for features like: compliance with RICS or ISO standards, integration with design software (Revit, etc.), cloud database of latest EPDs, level of automation and AI use, and the ability to model different scenarios (for example, end-of-life or module D options). In summary, WLCA software has matured to the point that even non-LCA-specialists can perform a credible whole-life carbon assessment with the right tool — making it easier for every project to embed carbon thinking from early-design through completion.