Types of Home Energy Audits

This blog originally appeared on the Rockwool R-Class Program website. ROCKWOOL – R-Class Builder Program – United States (English)

Energy audit, energy assessment and building diagnostics, what are the differences?

Part of my work is in a niche discipline in the residential construction industry where I test and inspect both new and existing homes for construction errors and other deficiencies that cause a home not to meet its owners’ expectations.  A home can have a comfort or cost to operate issue.  There may be moisture or indoor air quality issues that cause health problems for the occupants, or maybe there are structural durability concerns due to water infiltration.  Sometimes this testing and inspecting simply becomes an education session to teach the homeowners how their homes work.


There are three different types of analysis I perform, an energy assessment, energy audit and building diagnostic.  They are all related, but a little different.  The first two deal with the movement of energy in a structure, the last is usually more about the movement of moisture, but not always.  Let’s dig a little deeper into each.

Energy Audit 

Wikipedia defines an energy audit as an inspection survey and analysis of energy flows for energy conservation in a building.  I inspect and test a building (in my case, the building is always residential) to determine why the home’s energy performance does not meet the occupants’ expectations.  In other words, it’s almost always a comfort or high bill complaint.  An energy audit will include a questionnaire, several tests along with visual inspections to determine how the home was built and if there is an issue with either the building or equipment operating in the home or on the property.  (Not every problem I find is confined to inside the home.)  The questionnaire includes asking about comfort and moisture issues, the homeowner’s schedule (do they leave for work at the same time every day, or maybe they work from home), and the things they do in the home (how often they do laundry, run the dishwasher, etc…) Testing may include blower door testing, thermal imaging, duct tightness testing, testing electrical service panels for usage, checking ventilation rates, and a check of the indoor air quality among others.

Energy Assessment

An energy assessment on the other hand is an energy audit without testing.  I perform more energy assessments than energy audits.  I’m typically giving the customer my best guess as to why the home’s performance isn’t meeting their expectations based on a series of questions, a visual inspection and review of past energy consumption.  It’s a much faster service, and as you may have guessed, it’s also much less costly.  Most of the energy assessments I perform are through a local electricity provider, at no cost to their customer.  It’s a win-win for both the provider and customer, the provider shows they care and want to help, and the customer gets a free service and a bunch of energy saving devices like LED lightbulbs and low flow shower heads.  I’d estimate that 6 out of 10 energy assessments result in successfully finding most of the issues.  (Energy assessments and sometimes energy audits are available in areas of both the US and Canada at no or reduced costs.  Check with your local energy provider for availability.)

Building Diagnostic

A building diagnostic or building investigation is a little different, I’m dealing with a homeowner that has some sort of moisture issue with the home.  These issues can range anywhere from too high or too low humidity levels (water vapor issues), bulk water leaks, air leaks or capillary wicking of moisture through an assembly.  I perform a limited number of building diagnostics each year, they are a small but growing part of my business.  There is a subcategory of building diagnostics I perform called code compliant or code required testing.  This testing is a simple pass/fail test required by a code official to satisfy the building code requirements.  Blower door and duct tightness testing are most common, but I also have the tools to verify ventilation and air flow rates of HVAC equipment.


My first energy auditing training came in 2009, the education was provided by a local college and met the State of Minnesota’s required guidelines to be an energy auditor.  I’ve since taken education by the Building Performance Institute (BPI) in both building analysis and weatherization training.  I’ve also completed training for RESNET HERS Rater certification.  Continuing education events and attending builder conferences has allowed me to continue to learn.

The future of energy auditing is bright.

With the passing of the Inflation Reduction Act (IRA) in the United States, there will be a demand for more energy auditors.  Both builders and homeowners can benefit from the programs in the IRA legislation, but third-party verification will be needed.  Much of this verification will be performed by certified energy auditors and HERS raters, or possibly by community action programs such as the federally funded Weatherization Assistance Program.  Each state will be responsible for the IRA roll out and at the time of this writing, much of the planning is ongoing.  If you are interested in participating in any of the IRA programs, I suggest keeping an eye on local information.  How each of the programs is operated will vary from state to state.

Interested in becoming an energy auditor or HERS rater?  Start by visiting the Building Performance Institute’s (BPI) website at www.BPI.org or the Residential Energy Services Network (RESNET) www.resnet.us for more information on training opportunities.  There are a number of great websites dedicated to all the topics discussed in this post.  Green Building Advisor www.greenbuildingadvisor.com is one of my favorites.  Another is the Building Performance Association www.building-performance.org.

Stay tuned for my next blog post at the Rockwool R-Class website which will go into energy auditing in more depth.  I’ll cover a portion of my questionnaire, the testing I provide, and the common problems I see in many homes.

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