Date: October 1991

Author(s): J. Staib, G. Yuill, J. H. Willenbrock

Buildings consume approximately fifty percent of the energy associated with the total United States' energy bill each year. As energy supplies become more scarce and the prices of raw fuel as well as electricity continue to rise, the demand for energy-efficient construction in residential dwellings will continue to exist. It has been estimated that thirty to fifty percent savings can be realized in new residential construction alone without sacrificing comfort or convenience.

Many energy efficient materials, mechanical systems, and construction techniques are available in the residential building industry that are a good investment and can save energy, without detracting from the quality of the living space. However, conservation of energy has not yet become a universally accepted critical issue in the design and construction of houses. This situation is attributable to many factors which include the diverse nature of the industry and the variety of manufacturer's products.

The research for this report was divided into two parts. First, information about the different building materials and heating equipment associated with the residential construction industry was compiled and synthesized in a form that could be used by industry members. An energy-efficient house design was then introduced as a case study to determine the effectiveness of the various design options.

The second part of this research effort involved cost and energy performance evaluations on different configurations of the case study house using Williamsport weather conditions and State College prices. An initial cost estimate and energy load analysis for the base house was produced to establish a datum against which the results of the sensitivity studies could be compared. These studies were conducted by changing a single building element or mechanical system of the base house. Cost parameters and energy loads were re-evaluated to determine the effect of the change. Economic parameters that govern both the capital and operating costs of a house were also varied to demonstrate their effect on the life cycle costs. Finally, illustrative designs that utilized some of the most cost-effective alternatives were compiled and evaluated to facilitate the material and heating equipment selection processes used by energy-conscious Pennsylvania homebuilders.

There are many energy conservation features that can be incorporated into a house at little or no cost. The life cycle cost analyses that were performed in this report are important in determining which of these features are the most cost-effective. In conducting such analyses, builders and home buyers may begin to perceive energy saving improvements as good long term investments. A summary table has been included in the report that lists the most effective construction materials and heating equipment from an energy perspective.

A project that considers the energy consumption due to cooling as well as heating. It will include among the system options cooling and heat pump equipment as well as heating equipment. Similar results will be produced for a matrix of input data including the full range of weather conditions found in Pennsylvania, and the full range of utility rates.