Ask Two Countries, Get Two Carbon Numbers

Buildings account for ~37% of global energy-related CO2 emissions, but regulations focus almost entirely on operational energy. Embodied carbon (from material manufacturing, construction, and end-of-life) represents 20–50% of a building's lifetime emissions and is effectively invisible in decision-making because no globally comparable methodology exists for whole-life carbon (WLC) assessment. Existing WLC methods diverge in scope, system boundaries, assumed building lifespans, and data sources — making cross-building and cross-country comparisons meaningless.

As operational energy efficiency improves (through insulation, heat pumps, renewables), embodied carbon becomes a larger share of total building emissions — already 50%+ for high-performance new buildings. Without a valid measurement framework, embodied carbon cannot be regulated, incentivized, or optimized. The IEA convenes 12 countries on building energy codes but reports that WLC methodology divergence is the primary barrier to harmonized regulation.

The European standard EN 15978 provides a WLC framework (lifecycle modules A0–D), with a revised version expected in 2025. Finland, France, the Netherlands, and Denmark have mandatory or voluntary WLC requirements. Environmental Product Declarations (EPDs) provide material-level carbon data. However, EPDs for the same material vary 2–5× across databases. Only 39% of lifecycle assessment studies cover end-of-life phases, missing potentially 9–100%+ of additional embodied carbon. Major building components (fenestration systems, adhesives, MEP systems) have no EPD data at all. Module D (beyond-building-life benefits from recycling) is particularly contested — different methods produce contradictory conclusions about the same material. 60% of embodied carbon research originates from just 5 countries, leaving the Global South without representative data.

Harmonized WLC methodology with consistent system boundaries accepted across jurisdictions. Interoperable EPD databases with transparent uncertainty ranges. EPD coverage expanded to currently uncharacterized building components. Whole-building benchmark datasets large enough for statistical comparison by building type, climate zone, and region — enabling regulators to set meaningful thresholds.

A team could calculate the WLC of a single building using three different methodologies (EN 15978, RICS, LEED) and quantify how much the results diverge — identifying which methodological choices drive the largest differences. Alternatively, a team could develop EPD-equivalent carbon data for an uncharacterized building component category (e.g., adhesives and sealants) using manufacturer data and LCA modeling. LCA, building science, and data science skills apply.