Analysis of the impacts of energy conservation codes in new single-family homes

Within the 50 states some form of federal code or standard for energy conservation in new building construction is typically incorporated into state and local codes. Two of these codes, the Model Energy Code (MEC) and the proposed ASHRAE standard 90.2P are of special importance to the residential data base developed by the Gas Research Institute (GRI) because they influence thermal requirements and have either been recently updated or will be revised in 1992. In this study, we evaluate the impacts of these two thermal codes on the energy performance and energy consumption of prototypical new single-family buildings. Base case buildings, with characteristics typical of current building practices, are modified to meet the thermal envelope standards and are simulated with the DOE-2.1D building energy simulation program. In addition, we also model the effects of appliance and heating and cooling equipment efficiencies promulgated under the National Appliance Energy Conservation Act (NAECA) of 1987 and of the NAECA Amendments of 1988. We compare heating and cooling loads and energy use for the prototypical house for several cases: the base case, with 1980s vintage thermal envelope and appliance and equipment efficiencies; with ASHRAE 90 thermal requirements; with Model Energy Code thermal requirements; with NAECA appliance and HVAC efficiencies; and with combinations of the ASHRAE 90 Standard or Model Energy Code and the NAECA appliance and equipment efficiency improvements. The results provide a glimpse of how these standards will affect future end-use energy consumption in new single-family buildings.