A cold bridge (cooling bridge) is a range in construction units of a building, by which the warmth is faster outward transported, as by the other construction units. One differentiates between constructional and geometrical cold bridges. * Constructional cold bridges result from installations or materials with higher heat conductivity or missing thermal insulation, for example reinforced concrete compound units, which break through a dammed external wall. * Geometrical cold bridges result in itself for example by jumps or corners in otherwise homogeneous construction unit, if a larger exterior surface, by which the warmth flows off, stands for the inner surface opposite. Within the range of cold bridges the spacelateral surface temperature of construction units drops in the winter. When falling below the dew point temperature condensation water (condensation) precipitates. At cold bridges the danger of fungus growth exists.