In North America, the ATHENA® Impact Estimator for buildings is the only software tool that evaluates whole buildings and assemblies based on internationally recognized life cycle assessment (LCA) methodology. Using the Estimator, architects, engineers and others can easily assess and compare the environmental implications of industrial, institutional, commercial and residential designs–both for new buildings and major renovations. Where relevant, the software also distinguishes between owner–occupied and rental facilities. The Estimator puts the environment on equal footing with other more traditional design criteria at the conceptual stage of a project. It incorporates ATHENA’s own widely–acclaimed databases, which cover more than 90% of the structural and envelope systems typically used in residential and commercial buildings. It also simulates over 1,200 different assembly combinations and is capable of modeling 95% of the building stock in North America.