The complete carbon picture of a building across its entire lifecycle: embodied carbon from materials and construction, operational carbon from decades of energy use, and end-of-life carbon from eventual demolition or deconstruction, all added together. Assessing whole life carbon requires exactly the kind of rich, structured data BIM is built to hold - quantities, material types, expected service life, energy performance - pulled together from a single model rather than assembled by hand from separate reports.

It is increasingly what regulations and certifications like LEED and BREEAM are moving toward requiring, replacing older assessments that only looked at operational energy in isolation.