**Lifecycle assessment (LCA)**: A method to quantify the carbon emissions and other environmental impacts (such as acidification and air pollution) of assets or products over their whole lifecycle. **Lifecycle stages and modules**: Each lifecycle module (A1, A2...) describes a distinct phase in the lifecycle of an asset, and modules are grouped into stages (e.g. product stage consists of Modules A1–A3). **Environmental product declaration (EPD)**: A third-party verified, standardized document that provides the environmental impact of a product, based on the data from an LCA. **Greenhouse gas (GHG) emissions**: Emissions of gasses including carbon dioxide, methane and water vapor that trap heat in the atmosphere. The global warming potential (GWP) of these gasses is measured in CO2e (carbon dioxide equivalent). GHG emissions are commonly referred to as "carbon emissions". **Embodied carbon (EC)** : The GHG emissions associated with materials and construction processes throughout the whole lifecycle of an asset (Modules A1–A5, B1–B5 and C1–C4), excluding its operation. **Operational carbon (OC)** : The GHG emissions arising from all energy and water consumed by an asset in use, over its lifecycle (Modules B6 and B7). **Upfront carbon**: GHG emissions up to practical completion, excluding sequestration (Modules A1–A5). May also be referred to as "upfront embodied carbon" **Whole-life carbon (WLC)**: The total of all GHG emissions (and removals), including both operational carbon and embodied carbon , over the lifecycle of an asset, including its disposal (Stages A–C). Potential benefits or loads from future energy recovery, reuse and recycling (Module D) are reported separately from WLC. **Sequestration**: The removal and long-term storage of CO2 from the atmosphere in biomaterials such as timber. The carbon stored in these materials is known as biogenic carbon.