This document provides detailed guidance on the carbonation and carbon dioxide (CO2) uptake in concrete. This guidance is complementary to that provided in EN 16757: Product Category Rules for concrete and concrete elements, Annex BB. Typical CO2 uptake values for a range of structures exposed to various environmental conditions are presented. These values can be incorporated into EPDs for the whole life cycle for either: a functional unit, one tonne or one m3 of concrete, without necessarily having any detailed knowledge of the structure to be built. In the rest of the document, the data will be given per m3.