Cognitive Systems can be applied in architectural spaces to improve Built Environment performances basing on users’ needs. They can: 1) jointly monitor environmental conditions and human behaviours through Cognitive Built Environment (CBE) components; 2) use human-environment interaction models and related Key Performance Indicators to detect critical situations; 3) adapt CBE devices status to inform users on how to properly behave. This approach is applied to safety performances of outdoor (earthquake) and indoor (fire) scenarios, by proposing and testing solutions to support evacuees while reaching safe areas and rescuers’ support.