In this guide

What is an Energy Audit?

An energy audit is designed to find any potential energy losses and possible solutions for those losses in order to reduce your energy bills and improve your home’s efficiency. This may also be called an energy assessment or study, but the process is the same. This audit gives homeowners the full picture of their house and its deficiencies and offers professional advice from the auditor on how to improve efficiency. The end result will be a savings of between 5% and 30% on your annual energy costs if you make all of the suggested changes.

Energy Audit Costs Per Square Foot

Like many whole-home services, energy audits are sometimes priced by the square foot, since more area means more work. Some audits will have various pricing tiers for home-size ranges, while others will actually charge a dollar amount per square foot to get an exact cost for each separate home. For square footage pricing, the national average ranges from $0.12 to $0.35 per sq. ft. In the table below are the most common home sizes in the U.S. and their corresponding average cost range:

Energy Audit Cost by Type

There are different levels, or types, of energy audits that can be performed. The American Society of Heating, Refrigerating and Air-Conditioning Engineers, or ASHRAE, has designated three levels of audits to ensure all auditors follow the same procedure. In the table below, are the national average costs for each type of inspection. Below the table, is a more detailed explanation of what each audit includes:

ASHRAE Level 1 Energy Audit Cost

A Level 1 audit is also called a walk-through. Reporting and use of testing tools are limited as the auditor walks through a building to evaluate energy efficiency. These types of audits are usually only recommended for small buildings with low overall energy usage. Utility bills and interviews with property owners are included with this type of audit. The typical cost is $0.08 to $0.12 per square foot.

ASHRAE Level 2 Energy Audit

Level 2 energy audits require more analysis and reporting procedures. Equipment pieces are inventoried, with energy usage for each piece evaluated. Improvement costs are projected with a savings analysis of each measure documented. The auditor will look for the highest potential for energy savings and create long-term energy savings goals. This type of audit is most often recommended for larger buildings. A Level 2 audit will also include Level 1 procedures. Expect to spend $0.12 to $0.35 per square foot.

ASHRAE Level 3 Energy Audit

Level 3 audits are rarely done on residences. These audits are usually reserved for large and complex commercial buildings. A Level 3 audit will have all of the components of a Level 1 and Level 2 audit as well as a detailed analysis performed by the technician. Comprehensive surveys are performed along with hourly HVAC monitoring and analysis. Existing utility bills are reviewed, with sub-metering done by the company. You will pay about $0.36 to $0.50 per square foot.

Energy Audit Cost

In terms of labor, the costs are typically included in the total price of your energy audit, which can range from $0.12 to $0.35 per sq.ft. The audit process takes about 2 to 3 hours, on average, with more extensive audits lasting up to 4 hours or more. Note that it will sometimes take a couple of weeks to schedule one, so you may want to plan ahead if you are trying to meet a deadline for a rebate or incentive program.

Its cost includes the entire testing process and will depend on the level of audit you have chosen, as discussed elsewhere in this guide. The auditor will need to access the exterior, attic, and basement (if present), any crawl spaces, and all exterior walls and windows. They may also want to inspect your HVAC system or other major systems for inefficiencies.

An audit will include the assessment of your home, as well as a review of your annual energy bills and comparable data from similar homes. This will help them come up with a list of potential improvements, problem areas, and recommendations for energy improvements that you can make. In addition to the verbal recommendations from the auditor, you will typically get a detailed report about 7 to 10 days after the audit, which you can retain for your records and submit for improvement or rebate programs.

Energy Audit Procedure

During the process of the energy audit, there are several things that will be done that may incur charges. Of course, many of these are lumped into the flat rate or square-footage rate being charged for the audit in the first place. In order to get an accurate picture of your home’s energy usage, an auditor will inspect the elements detailed below. Bear in mind that, regardless of the extent of the work done, your audit should not cost more than 10% of your annual energy bill.

Utility Bill Examination

All of your utility bills from the past year can be analyzed by your auditor to determine if you're paying too much to heat or cool your home. This is typically done by comparing your utility costs to the average costs paid by homeowners in your area. An interview is also conducted to determine areas of concern.

Room-by-Room Examination

Auditors should typically walk through each room of your home and conduct a thorough visual inspection of the windows, appliances, and, if possible, the insulation. The exterior of the building is also assessed to help the auditor find any issues such as damage to the roof, eaves, or windows.

Blower Door Test Cost

Blower door tests are designed to check the airtightness of your home and identify any leaks. They manipulate air pressure indoors, drawing air through unsealed cracks and openings. This is done by mounting a large fan onto your home's front door. A blower door test is normally included in the cost of a standard energy audit.

Duct Testing Cost

This test is performed to check for air leaks and energy efficiency in the ducts throughout the home. Special tools are used to manipulate air pressure while the system is running to identify leaks, inconsistencies, and other duct issues. This process is not always included, but it is a critical step in making sure the HVAC system is as energy-efficient as possible. If not included, duct testing costs range from $50 to $200, with cheaper rates when included as part of an energy audit.

Infrared Imaging

Infrared imaging equipment is used to show where heat is escaping and cold air is entering. Repairing problem areas identified through infrared imaging can lead to savings of up to 20% in heating costs. This is not typically included in a standard energy or heating audit and will incur an additional cost if it is desired. When it isn’t included in the costs, IR imaging will typically add about 50% to your audit, with a national average of around $200 for a limited moisture scan.

HERS Test Cost

A HERS test, or Home Energy Rating System test, is a procedure that was devised by the California Energy Commission. This test was designed to verify energy efficiency and indoor air quality as it relates to the installation of HVAC equipment. However, it can also be used in an energy audit to satisfy state requirements or identify other potential problem areas. The average HERS rating cost is $1,500 to $3,000, depending on the size of the home and extent of testing done.

Energy Efficiency Solutions

Once the energy audit has been completed, you will need to discuss the suggestions and concerns of the auditor. Ask questions and get as many explanations as you can so you can give your home the improvements it needs. Establish what your priorities are and resolve small issues promptly. The following table will show you various energy improvements that you can make, along with their average costs. And below that, each fix is discussed in detail.

Installing Energy Star Certified Appliances

The biggest impact on your home’s energy savings is evaluating the need for new appliances. Replacing old and inefficient equipment and appliances with Energy Star certified products will give you up to 30% in energy savings. And these appliances typically only cost about 5% to 10% more than nonrated appliances. You may spend as little as $100 for a new energy-efficient microwave or more than $4,000 for an Energy Star certified top-of-the-line fridge, so costs vary significantly.

Weather-Stripping Cost

Weather stripping may be done as a part of a comprehensive air sealing process or on its own. The process involves adding an extra layer of insulation made specifically for sealing cracks and leaks to all of the doors and windows. These are common places where energy inefficiency is high, because weather stripping can wear down over time and require replacement. Typically, weather stripping alone will cost an average of $168 to $250, depending on the extent of the work.

Smart Thermostat Installation Cost

Adjusting equipment settings, adding timers, and installing thermostat controls can result in savings of 50%. They allow you to set the temperature from a mobile device and to preset times for heating and cooling periods. As an example, if the home is unoccupied during the day, you can set the air conditioner to 78°F and then schedule a more comfortable temperature before you arrive home. Installing a smart thermostat costs around $300, according to the national average.

Storm Window Installation Cost

Adding storm windows can further increase your energy efficiency of your home by as much as 33%. Storm windows add an extra barrier to the windows in your home that can accommodate them and are specifically designed to help mitigate energy loss and improve comfort. They typically cost about $350 per window, on average.

Home Air Sealing Cost

Air sealing your home is the best way to improve energy efficiency. In this process, a technician will inspect the entire home and identify any cracks, leaks, or other places where air might be leaking. The savings can be as much as $150 per year, and the process, on average, costs about $350 to $600.

Many homeowners worry that after air-sealing, their house might be too "tight" to breathe. This concern is based on the old misconception that some drafts and air leaks are necessary for a home to have healthy ventilation. In reality, there's nothing to worry about when your home is tightly sealed. An efficient home is tightly sealed but also has controlled ventilation installations. Relying on air leaks to provide your home's ventilation runs the risk of long-term damage as well as uncontrolled energy waste.

Windows Replacement Cost

In the event of serious leaks or efficiency losses, new windows might be in order. While installing new windows may involve a variety of costs, it will significantly improve the efficiency of your home. Typically, window replacement costs an average of $650 to $1,500 per window for standard single-pane double-hung windows without the addition of storm windows.

Attic Insulation Cost

Insulating the attic is a sure way to save energy. After all, heat rises, and much of the loss in the home goes right out the roof. With proper attic insulation, you can save up to 25% or more on your energy costs. Replacing insulation also increases the home’s value. Costs will vary by the size of your attic, with an average in the range of $1,700 to $2,000.

Energy Efficiency Problems

There are several common issues, small and large, around the home that can impact energy efficiency. These issues are all too common for many homeowners. Often, these problems are identified in an energy audit, and most are fairly simple to resolve. Below is a list of the most common issues and how they are resolved, along with costs provided where available:

Inefficient Lighting

Having old bulbs, light fixtures, and wiring can be a major source of energy consumption in a home. Incandescent light bulbs were most often used by homeowners before the 2000s. Incandescent light bulbs use almost five times the amount of energy as LEDs. Rewiring may be needed if the home is older than 40 years. Older electrical systems were not designed for energy efficiency. Older 100 amp electrical panels may also need replacement with 200 amp models. Replacing the lighting in your home could be as cheap the cost of a few bulbs.Many people need to spend only $50 to $100 on LED and energy-efficient lighting upgrades, including simple bulb or fixture replacement. If you need more than new bulbs, it could cost as much as $8,500 to rewire the entire home or $2,500 to replace the electrical panel.

Inefficient Appliances

Equipment that is old, has a low energy rating, or just isn't right for your home type or climate can consume far more energy than necessary. Energy Star ratings were created to help consumers avoid choosing appliances that aren’t energy-efficient. These ratings are especially important when buying clothes dryers, refrigerators, air conditioners, and water heaters. These appliances draw the most energy compared to other household appliances. Replacement costs vary, and, depending on the exact model and style chosen, you may spend as little as $100 on a new energy-efficient microwave or more than $4,000 for an Energy Star certified top-of-the-line fridge. On average, homeowners spend about $1,500 to $2,000 on replacing appliances for energy improvements.

Home Air Leaks

It's estimated that the average homeowner wastes as much as $350 in utility costs due to air leaks. Air leakage occurs when the air leaves the home through cracks and holes. Caulking and weather stripping can be added or upgraded to seal any openings and reduce the number of air leaks. The average cost to seal air leaks ranges from $350 to $600.

Inadequate Insulation

Most homes lack enough insulation to keep them energy efficient. It's not uncommon for an auditor to discover that a home is completely missing insulation in certain sections. Insulation is rated in terms of R-values. The higher the R-value, the better the insulating effect the material provides. Popular insulation types include fiberglass, wool, cellulose, polystyrene, spray foam, and cotton. If the material currently installed is damaged, missing in areas, or doesn’t have a high R-value, new insulation is likely needed. Insulation costs range from $0.12 to almost $7 per square foot, depending on the type of insulation you choose. The national average for a whole-home insulation project is between $3,500 and $4,500.

Prep Work for an Energy Audit

You will need to do some minimal preparation before your energy auditor arrives for the inspection. Windows and doors should be closed and latched securely. If any windows or doors are broken, point these out to the auditor ahead of time.

Any belongings you have that are blocking access to the attic, basements, and crawl spaces must be cleared out. Nothing should be blocking appliances, since the auditor will need easy access to furnaces, boilers, and water heaters.

Make a list of any energy problems you've noticed in the summer and winter, such as drafts or excessively high energy usage. Have copies of your yearly energy bills on hand so that they are ready to be examined by the auditor, who will typically want to see the past 12 months’ bills.

Enhancement and Improvement Costs

PFT Air Infiltration Measurement Technique

The PFT is a long-term test designed to measure the airtightness of your home and is often recommended as a supplementary upgrade to the blower door test. Your auditor will install an emitter and receiver inside your house. This equipment will emit a trace of 100% safe, non-toxic gas and then later absorb it to measure how much of the gas leaked out of your home over time. This test can give a more advanced assessment of your home's airtightness, as well as any air pollutants. PFTs are typically only included in extensive audit packages, which can cost more than three times as much as an average audit.