Claims about the environmental performance of building products are easy to make but difficult to substantiate without a transparent measuring system. Environmental profiles measure the impacts of a construction material, product or building system throughout its life ? not only during its manufacture, but also its use in a building over a typical building lifetime. This includes its extraction, processing, use and maintenance and its eventual disposal. The Environmental Profiles Methodology assesses environmental indicators that reflect impacts occurring globally, regionally and locally - in the air, in water and on the land, impacting humans and the environment. These impacts are assessed under a range of issue categories and normalized by reference to European data. They are weighted to generate a measure of environmental impact as a proportion of the annual impact of a European citizen.