Energy Audits Benefit Home Buyers


A home energy audit is a professional service that evaluates the energy efficiency of a house.  The tightness of a home’s building envelope; its walls, floors, ceilings, doors and windows, are tested using calibrated equipment to measure pressure differences, and by the use of infrared cameras to measure temperature differences.  The energy audit seeks to find opportunities to reduce energy consumption while maintaining or improving comfort. 

For the majority of home buyers, their new home is probably the largest investment they will ever make, and one of the largest ongoing expenses of owning that home is the cost of the energy required to operate and live in it comfortably.  The “gas mileage” a home gets is fast becoming a concern for many home buyers and they are certain the cost of that “gas” will not be going down in the future.  Although having an energy audit or having specific energy tests performed on a home has not always been a part of the buyer’s due diligence process, this trend is rapidly changing as consumers are increasingly more energy conscious, and becoming aware of the availability of quantitative testing services.

Having a comprehensive energy audit should be a part of the due diligence process for every home buyer.  Knowing prior to closing how well a house performs regarding outside air penetrations, comfort to the homeowner, areas of energy waste, and getting estimates of the costs to remedy poor performance is critical in making an informed decision.  In addition to discovering any latent defects in the home’s performance, results from an energy audit along with repair cost estimates could allow the purchase price to be renegotiated, or result in the seller offering concessions that may offset the cost of the energy audit, possibly even the repair costs.

Building performance science, aided by technology along with our nation’s need and desire to conserve energy, has resulted in an increasing number of qualified companies with certified, trained professionals to meet this demand.  A variety of auditing services and fees are now available to homebuyers.  Fees can range from $125 to $450 and higher depending on the house size and the services requested.

A comprehensive whole house energy audit involving a full analysis of the home’s building materials, appliances, lighting, plumbing fixtures, its past energy usage (typically for the past 12 months), and performing an array of diagnostic tests is one option.  The report from a comprehensive whole house energy audit provides the buyer with the most data concerning the home’s performance, and will include a prioritized list of suggested improvements based on the savings rate of return on improvement costs.  

Other options are individual component testing, or a combination of tests from the whole house audit.  While not resulting in the exhaustive cumulative analysis obtained from a whole house audit, they provide the home buyer with valuable information and will naturally cost less.  The results of these individual tests may also include improvement cost estimates, if not, the auditor should be able to provide a list of recommended contractors able to give estimates based on the findings. 

One of these individual tests employs a diagnostic tool called a Blower Door.  It consists of a calibrated variable-speed fan that is mounted in an adjustable frame temporarily placed in an exterior doorway, and is used to measure air pressure differences.  This tool not only allows the auditor to quantify the volume of outside air that infiltrates a home per minute, but it also aids the auditor in identifying the locations of air infiltration.

Thermal imaging using an infrared camera is another valuable tool for analysis.  Hot or cold air cannot be detected by the naked eye.  An infrared camera has the capability of detecting a difference in surface temperature of less than .08 C.  Sagging insulation or the absence of insulation behind walls and ceilings cannot be readily seen, however it does cause a variance in surface temperature.  These temperature differences displayed in a color spectrum become visible.  This type of energy inefficiency that can be corrected would otherwise go unseen and unnoticed, except for the ongoing energy bill.  Adding insulation is relatively inexpensive when compared to the energy costs due to the lack of insulation.  In addition to highlighting hidden energy problems, thermal imaging can also reveal previously unseen and undiscovered moisture issues resulting in surface temperature differences.

The Duct Blaster, a diagnostic tool similar to a Blower Door, measures the percentage of conditioned air that escapes from leaky duct work into a home’s attic or basement; a problem that is mistakenly considered to be associated with older homes, but is also a common problem in newer homes that do not have testing done during and/or after construction.  According to the Department of Energy a typical house loses 20% of expensive conditioned air through leaks in the ductwork before reaching targeted living areas.  It is not uncommon for duct systems in existing homes, as well as in new construction, due to faulty installation, to have more than 40% duct leakage.  This is wasted energy and money that a seller probably isn’t even aware of, but a buyer can discover by having some simple testing done prior to closing. 

The time required at a home to gather data and perform a comprehensive whole house energy audit is usually 3 hours or more depending on the house size.  Additional time is then needed to compile a report.  In most cases a complete audit report may be available within 24 hours.  Individual component testing will typically take a half hour to an hour and a half with the results being left with the client at the end of testing.

Homebuyers and homeowners should be aware of how efficient their homes are in providing comfort.  The ability to obtain professional energy analyses and accurate valuable assessments has never been more accessible.