The study focusses on two aspects of building envelopes. Firstly, on the computation of steady and periodic thermal characteristics of the building envelope (walls, roofs and window glasses) under the influence of local weather elements and secondly on the various considerations for the energy-efficient design of Malaysia building envelopes. The fabrication of an experimental rig to measure the thermal conductivity of building materials is presented in detail. The overall Thermal Transfer Value (OTTV) as an index for the energy efficiency of the building envelope is developed. Finally energy conservation standards for Malaysia building envelopes are proposed.