Residential Home Audits: An Empirical Analysis of the Enersave Program

The purpose of residential home audit programs is to encourage energy conservation by providing homeowners with information concerning retrofit actions which are economically feasible. One particular type of home audit program, the Class B audit, is based on a computerized analysis of the home. This study examined the impact of one Class B audit, the ENERSAVE program operated by the Canadian federal government. A longitudinal analysis of approximately 1400 households, a majority of whom participated in the program, concluded that the ENER$AVE program had little or no effect on homeowners' conservation activities. These results coupled with other findings question the effectiveness of Class B audits in general. To combat rising energy costs many homeowners consider improving the energy efficiency of their homes through retrofitting. One of the barriers they may face is a lack of knowledge as to what actions should be taken. Government departments, utilities, and others have recognized this and have offered home audits as a means of reducing or removing this knowledge barrier and encouraging 265 © 1983, Baywood Publishing Co., Inc. doi: 10.2190/8H0K-D3QC-TGY8-9YCJ http://baywood.com 266 / G. H.G.McDOUGALL, J. D.CLAXTON AND J.R. B. RITCHIE energy conservation. Home audits can generally be described as a service which, based on an assessment of the energy integrity of a dwelling, provides the user with a number of recommendations concerning retrofit actions. A wide variety of home audit programs have been implemented in the United States and Canada. For example, in one review, twenty-two different home audit programs were identified and they represented just a small fraction of those in existence [1]. The programs range from home planning kits which provide the "do-it-yourself consumer with ideas and guidelines for energy savings to formal home energy audits conducted by a trained energy evaluator who makes specific recommendations and, in some instances, helps the homeowner find contractors and funds to complete the recommended retrofit actions. One issue with these programs is their effectiveness in achieving energy conservation by homeowners. While the cost-per-household of providing information can be determined (in some cases less than $1.00 per household for simple "do-it-yourself information kits to over $125.00 per household for an inspection by a trained auditor), the effectiveness in terms of energy conservation actions and actual energy saved is far less certain. The objective of this article is to examine the effect of a computerized audit, the ENER$AVE program, operated by the Canadian Federal Government. Since the inception of the program in 1977, a personalized computer home energy audit has been provided for over 300,000 households in Canada. Through an analysis of a sample of 1,451 households, some of whom participated in the ENERSAVE program, and all of whom were questioned two years later concerning conservation actions taken, an assessment of the ENERSAVE program will be presented. Specifically, the analysis will consider: • if households who participated in the ENERSAVE program were more interested in conservation; • if completion of the ENERSAVE questionnaire itself acted as a stimulus for conservation activities; and • if conservation recommendations received by households via ENERSAVE acted as a stimulus for conservation activities. The article begins with a discussion of the homeowner's decision to retrofit and how the different types of home audit programs might influence the decision. This is followed by a description of the ENERSAVE program, the research design, and analysis. Conclusions are then drawn based on the preceding discussion and analysis. BACKGROUND The homeowners decision to improve the energy efficiency of the dwelling is somewhat complex because of the technical expertise required and the number of actions that could be taken. For example, insulation can be installed in a RESIDENTIAL HOME AUDITS / 267 number of areas, weatherization can be done, and furnace improvements can be made. The homeowner cannot determine which actions are economically worthwhile without some specific information on the condition of the dwelling and possibly some rank ordering of the economic payoffs from various actions. Home audits are designed to provide part or all of this information depending on the class of audit undertaken. As shown in Table 1, there are three general classes of home audits, the simplest being a do-it-yourself audit (Class C), a second level audit where the homeowner completes the home description information and the analysis is done with the aid of a computer program (Class B), and the most sophisticated (Class A) involving a home inspection by an energy auditor. The major variations occur within Class A audits where "packages" may be introduced which provide the homeowners with a complete insulation service including financing and guarantees for both workmanship and materials. Further, the individual conducting the energy audit may act merely as an information provider or as a salesperson who encourages the homeowner to invest in the recommended conservation actions. There has been no systematic study of the relative effectiveness of the three classes of programs. Class B and C audits have been criticized because the analysis of the heating system is often based on inadequate information. In particular, because of underestimating by-pass heat losses, do-it-yourself handbooks (Class C) or computer programs (Class B) will usually fail to give people advice that will minimize the cost of improving the energy performance of the house [2]. Further, Class B and C audits seldom make recommendations concerning improving the air tightness of the home, the factor some consider most critical in home energy efficiency [3]. These audits have also been criticized because of their failure to recognize that each house is, to some extent, unique and requires some degree of individual attention. Another problem is that Class B audits base their recommendations on the heating cost estimates provided by the homeowner. Unfortunately, many homeowners' estimates of these costs are frequently incorrect [4]. On the other hand, while Class A audits can be tailor-made for both the home and homeowner, the cost is considerably higher than either a B or C audit. There is no empirical evidence to show that Class A audits have achieved greater homeowner conservation actions or energy savings than either Class B or C audits. Of particular interest would be a cost/benefit analysis across the three types of audits to determine the proportion of homeowners among a target population who had an audit conducted and, of these, the proportion who engaged in conservation actions and the savings in energy that resulted. The fundamental question to be answered is whether or not any type of home audit can be a cost-effective means of promoting retrofits of homes [5]. Only limited research is available on the evaluation of home audit programs and usually only one type of program was examined. For example, study of 268 / G . H . G . M C D O U G A L L . J . D. CLAXTON AND J. R. B. RITCHIE