Thermographic infrared photographs showing serious heat loss in buildings across European countries. The thermographic camera shows details the eye cannot detect. Yellow and red areas are parts of the buildings which have a higher surface temperature than the rest. These are the places where heat is leaking through gaps and poor insulating materials and valuable energy is being lost, resulting in both damage to the environment due to a waste of energy resources and unnecessary costs for home owners and tenants. A typical weak point is window panes and frames and thin walls below windows, where radiators are commonly positioned and insulation should be optimal.