Review of international regulations governing the thermal insulation requirements of residential buildings and the harmonization of envelope energy loss

Within the current regulations, the thermal transmittance is the only factor that is used to compare the thermal insulation of buildings. However, this paper demonstrates that the thermal transmittance is not a valid parameter for the comparison and harmonization of the envelope energy losses because countries set different transmittance values for each climate zone, which are defined on the basis of different ranges of degree-day variation and are calculated using different base temperatures. Furthermore, this paper proposes a new methodology that can be used to regulate the thermal insulation of buildings to ultimately harmonize the envelope energy losses across all countries.