What Is a Home Energy Audit?

Most of us know how much energy our homes use because we see it on a utility bill. What that bill doesn't tell us is exactly where the energy is going—or whether parts of the house are making the heating and cooling systems work harder than necessary.

That's where a home energy audit, also called a home energy assessment, comes in. Rather than focusing on one appliance or one utility bill, an assessment looks more broadly at how the home uses and loses energy. Depending on the type of assessment, that may include everything from insulation and air leakage to heating and cooling equipment, windows, doors, ductwork, and other parts of the home.

The goal isn't to pass or fail your house. It's to better understand how the home is performing and identify areas that may be worth a closer look.

What Actually Happens During an Energy Audit?

A home energy audit typically begins with an evaluation of the home and its energy use. According to the U.S. Department of Energy, an assessor may start with a walkthrough to understand the home's characteristics and how energy is being used. The assessment may also include an inspection of heating and cooling systems and other areas that can influence energy performance.

Exactly what happens depends on the type and scope of the assessment. Some are relatively straightforward visual evaluations, while more comprehensive assessments may use diagnostic equipment to gather additional information about how air and heat move through the house.

That distinction is important because "energy audit" doesn't necessarily describe one identical service performed at every home. If you're considering one, it's worth understanding what a particular assessment includes before it begins.

How Can Someone Tell Where Your Home Is Losing Energy?

This is probably the most interesting part.

One tool an energy assessor may use is a blower door test. A calibrated fan is temporarily fitted into an exterior doorway and used to change the air pressure inside the house. That allows the assessor to measure the home's airtightness and help locate areas where outside air may be entering through unintended gaps or openings.

Another tool is an infrared camera. Instead of seeing what's physically behind a wall, thermal imaging detects differences in surface temperature. Those patterns can help an assessor identify areas that may warrant further investigation, such as possible air leakage or insulation irregularities. The Department of Energy notes that infrared scanning and blower-door testing are often used together.

An assessor may also evaluate ductwork or heating and cooling equipment as part of a more comprehensive assessment.

What Parts of the House Might Be Evaluated?

Energy performance involves more of the home than most people realize.

Windows and exterior doors can influence air movement. Insulation can affect how readily heat moves between conditioned and unconditioned spaces. Ductwork can influence how efficiently conditioned air reaches different rooms. Heating and cooling equipment plays another role, as do ventilation and the home's overall construction.

An assessor isn't necessarily looking for one big problem. Often, understanding a home's energy performance means looking at how several smaller components work together.

That's also why two homes of similar size can use energy differently. Age, construction, equipment, insulation, improvements, orientation, household habits, and other factors can all play a role.

What Happens After the Assessment?

Once the assessment is complete, the homeowner should receive information about what was found and potential areas for improvement. The Department of Energy's consumer guidance says an assessor should provide a report of findings and ideas for improvements after the assessment.

That doesn't mean you're obligated to make every suggested change.

Instead, the information can help you understand which areas of the home may deserve attention and allow you to decide what, if anything, makes sense for your property, priorities, and budget. Some findings may point toward relatively simple improvements, while others could involve larger projects that a homeowner chooses to consider over time.

Is an Energy Audit the Same as a Home Inspection?

Not quite.

A general home inspection and a home energy assessment have different purposes. A home inspector evaluates many visible components and systems of a property as part of a broader inspection, while an energy assessment specifically focuses on how the home uses energy and factors that may affect its energy performance.

They can provide different kinds of information about the same house, which is why one shouldn't automatically be treated as a replacement for the other.

Why Might a San Diego Homeowner Be Curious About One?

San Diego homes come from many different eras of construction, and the way we use our homes has changed significantly over time. Some properties have been renovated repeatedly, while others retain much of their original construction. Heating and cooling systems, windows, insulation, solar installations, appliances, and other components can also vary widely from house to house.

An energy assessment gives a homeowner a way to look at those pieces together rather than guessing based solely on a monthly utility bill.

And that's really the value of understanding what a home energy audit is. You don't have to assume your house is inefficient, and you don't need to start replacing things simply because they're older. An assessment is information—information that can help you better understand how your particular home is working.

Sometimes getting to know your house isn't about finding something wrong with it. It's simply about understanding what's happening behind the walls, above the ceiling, and every time the heating or cooling system turns on.

This article is intended for general educational purposes. The scope, methods, findings, and recommendations of individual home energy assessments vary. Homeowners should consult qualified professionals regarding their particular property.