Blog Post

The Costs and Quality of Home Energy Audits: What Homeowners Say

Aug 11, 2014 | Margaret A. Walls, Karen L. Palmer, Peter Hansen

This is the first post in a new series on our survey of homeowners as part of RFF’s Energy Efficiency Information Initiative. Here we focus on what’s included in an energy audit and how much it costs. In the second post, we’ll reveal if people followed their auditors’ recommendations. In the third post, we’ll focus on some differences among homeowners who had an audit versus those who hadn't.

Figure 1. Percentage of People Whose Audits Included these Characteristics
Figure 1. Percentage of People Whose Audits Included these Characteristics

Building scientists and energy efficiency experts have a message for homeowners: there are a number of cost-effective improvements that can lower our energy bills, from simple weather stripping and air sealing to upgrading to a new high-efficiency furnace. But many homeowners don’t know where to begin. They might know they have an old furnace, but they have no idea how effective the attic insulation is, where all the air leaks are, and which improvements are likely to pay off.

This is where home energy audits come in. A professional can determine where a house is losing energy and how to correct the problem. Auditors look for air leaks all around the home, evaluate air ducts for leaks (if the home has ducts), assess insulation in the attic, crawlspace, walls, and around pipes, and evaluate heating, air conditioning, and water heating equipment. They may use special techniques, such as a blower door test to manipulate air pressure in the house and draw air through unsealed cracks and openings, and infrared imaging to show where heat is escaping.

However, only about 4 percent of the homeowners surveyed in the US Department of Energy’s 2009 Residential Energy Consumption Survey reported having an audit recently. Even among people who have had audits, the follow-up with retrofits and improvements is usually incomplete. If energy efficiency investments pay for themselves in energy savings, why aren’t more homeowners taking advantage of these opportunities?

We recently surveyed 1,784 homeowners across 24 states to help answer this question. A total of 566 respondents said they had an audit in the past four years (our survey technique involved a stratified sampling approach to ensure we got a large enough number of people with audits to be able to statistically analyze the data). Of those who hadn’t, 29 percent said they had “never heard of them” and 16 percent said that they “had heard of them but didn’t know anything about them.” This finding alone suggests that information (or a lack thereof) is probably playing an important role in energy efficiency decisions.

We asked the respondents who had audits about what the auditor’s assessment included and how much the audit cost. As seen in Figure 1, almost 80 percent of respondents reported that their auditor “personally showed them trouble spots” but only 26 percent were provided photos of the trouble spots.

Only 64 percent of homeowners reported that their audit involved a blower door test, which is standard practice for a quality home energy audit and required by the Building Performance Institute (BPI). In fact, in our 2011 survey of home energy auditors, 91 percent reported that they use blower door tests fairly often or always. Similarly, 80 percent of auditors in the 2011 survey said that they analyze past energy bills fairly often or always and 63 percent use infrared imaging fairly often or always; in this survey of homeowners, the corresponding numbers are 64 percent and 56 percent. All of those auditors in the 2011 survey were BPI certified and many were members of Efficiency First, a trade association that develops best practices and advocates for the home energy efficiency workforce. Our current survey seems to suggest that many homeowners may be using auditors who are not BPI certified. Certainly it shows that not all auditors are using the same techniques and performing the same services. People in our two pre-survey focus groups also reported quite different audit experiences.

Figure 2. How Much People Paid for Their Audits
Figure 2. How Much People Paid for Their Audits

We also asked people in our survey how much they paid for their audits and got some unexpected responses. As shown in Figure 2, most people in our survey got their audits for free. In our 2011 survey of auditors, the average price (excluding any government incentives, discounts or rebates) was $349. Thus, most homeowners in our sample received heavily subsidized audits. These subsidies could come from utilities or from local government programs to promote energy efficiency. For example, in Washington, DC, the DC Sustainable Energy Utility has offered free audits to city residents. It’s also possible that some of the survey respondents could be part of the federal Weatherization Assistance Program, which provides free audits and free or heavily discounted energy improvements and retrofits to income-eligible households. However, the income levels of the respondents in our survey who reported paying zero are mostly too high to qualify for this program.

Are these free audits different from the paid ones? In particular, are they less likely to include a blower door test, energy bill analysis, and other features that we asked about? We looked into this and the answer is yes. Among respondents who paid for their audits, 83 percent had a blower door test compared to only 55 percent of those who got the audit for free; 71 percent of paid audits included infrared imaging while only 51 percent of free audits used this test. Similar results show up for analyzing bills, showing pictures, and so on.

In the next blog post, we’ll describe what we uncovered about audit follow up. What improvements and retrofits did the auditors typically recommend and did homeowners follow those recommendations? Does audit quality, as measured by the techniques and services included in Figure 1, affect follow-up? Stay tuned for more.