Joints can cause significant heat loss. In winter, warm, moist air escapes to the outside via areas that are not tightly sealed, i.e. joints and cracks. This leads to the air cooling down and humidity condensing, which can give rise to the formation of mould in the recesses. In order to detect heat loss, thermal imaging is recommended.
An energy retrofit of a building (insulating the façade and roof, as well as replacing the windows) seals the building more tightly and can thus improve energy performance.