The Homeowner’s Guide To HERS Testing

If you’re a homeowner concerned about your property’s energy efficiency, a Home Energy Rating System (HERS) test can offer you some valuable insights. The HERS score provides a thorough evaluation of how energy efficient your home truly is.

HERS testing can benefit you whether you’re planning to sell your home, upgrade it or build a new one. In many locations, a HERS test is a requirement for new construction, remodeling and renovations. The test makes sure the building meets current energy efficiency standards. If you’re budgeting for upgrades, HERS testing helps you find your home’s biggest energy efficiency weak points. Taking care of these issues first on your home improvement list will give you the best return on your investment.

In this article, I’ll explain the significance of a HERS rating and when it’s beneficial to have testing done to determine yours.

Why Your Home’s HERS Rating Matters

If you’re preparing to sell, knowing your home’s HERS rating helps you develop the selling price by factoring in the cost of future energy bills. Proof of the home’s energy efficiency is a strong selling point. Invest in energy efficiency upgrades, such as air sealing and adding insulation, before testing to help achieve a good rating that attracts buyers.

When you’re building a new home or buying an existing one, the HERS rating lets you know what to expect in terms of future energy bills and costs to make upgrades. A home with a good HERS score typically commands a higher price than average homes. The larger investment pays off through lower energy bills and increased comfort over time.

HERS got its start in 2006, when California set ambitious goals to reduce greenhouse gases. That year, the Residential Energy Services Network (RESNET) created the HERS Index to help homeowners and buyers reduce their energy use.

The evaluation process involves running tests on features such as the heating and cooling systems, appliances, walls and windows to evaluate their energy efficiency. Data from these tests are combined to calculate a rating on the HERS Index. A score of 100 relates to the standard home, known as the HERS Reference Home, which is based on the 2006 International Energy Conservation Code.

The lower the HERS rating, the more energy efficient the house. Every point of the rating represents a 1% difference in energy efficiency compared to the HERS Reference Home. A rating of 100 means the house is up to code. Most newly built homes achieve a rating of around 100.

For homes a few decades old with few upgrades,130 is a typical rating. That means the house is 30% less efficient than the HERS Reference Home. For a very old, inefficient house without upgrades, the rating can theoretically reach 200 or even higher, meaning it uses twice the energy as the Reference Home.

With a HERS rating of 85, which is at least 15% more efficient than the standard, a home meets the Environmental Protection Agency’s (EPA’s) requirements for the ENERGY STAR designation. Most newly built homes with extra energy efficiency features meet this requirement.

At a HERS score of around 70 (30% more efficient than the 100 standard), you’ll find new or upgraded older homes that have a few energy efficiency improvements such as extra attic insulation, a high-efficiency heating and cooling system and storm windows.

Serious attention to green building can reduce the rating to 50 or lower. Homes with these ratings have features such as modern, high-efficiency appliances, optimal insulation throughout the building, and high-efficiency windows and doors.

A net-zero-energy home, which produces as much renewable energy as it consumes, gets a HERS score of zero. Achieving this score requires not only having energy-efficient features, but also a means of producing renewable energy such as solar panels.

What To Expect From HERS Testing

A HERS test must be performed by a RESNET-certified HERS Rater. Your heating, cooling, and ventilation systems should be fully operational when the test begins. The process usually takes between two and four hours. During this time, the Rater performs both visual inspections and diagnostic testing on the parts of your home, as described below, that affect its energy efficiency:

• Heating and cooling system — The rater will note the system’s efficiency rating and make sure it’s running optimally. This includes verifying the refrigerant charge and assessing the thermostat.
• Vents and ductwork — Done along with tests on the heating and cooling system, this involves measuring airflow velocity and testing for duct leakage.
• Water heating system
• Appliances
• Attics, foundation, and crawlspaces
• Ceilings and roof
• Exterior walls, windows, and doors
• Floors over unconditioned spaces, such as over the garage or cellar

Other tests include the blower door test to measure the building’s airtightness and check for leaks, as well as use of infrared scanning to spot areas of energy waste due to insufficient insulation.

The HERS rater compares test data from your home to a version of the HERS Reference Home that’s the same size and shape and is located in the same climate and general environment. From this, they’ll determine where your home scores on the HERS Index.

If your home scores above average, meaning it’s less efficient than most, consider making some repairs and upgrades to improve your comfort and save money. Use your test results to find your home’s biggest energy leaks and perform a cost-benefit analysis of possible improvements. Many raters even provide a list of upgrade recommendations with a cost-benefit analysis of each as part of the HERS testing process.

For new construction, you’ll need a preliminary projected HERS rating. To calculate this, a certified HERS rater uses computer modeling to gather data based on how the house will perform if built according to plan. This data is used to calculate the projected HERS rating. During construction, the HERS Rater checks to make sure the house is being built as planned. Once the house is built, the HERS Rater runs tests and collects data to confirm the projected rating.

By showing how your home’s energy efficiency stacks up against modern standards, HERS testing helps you prioritize upgrades and remodeling work and guides you in setting a selling price.

So, Should You Find Out Your Home’s HERS Rating?

There are several reasons you should have a HERS test performed. A HERS test gives you useful insights into how efficiently your home uses energy so you can make smarter decisions, whether you’re getting ready to sell, buy, build or spruce up your home.

This score not only influences your future home energy bills but also affects its marketability and how comfortable it feels. If you’re undertaking renovations or having a new home built, applying HERS standards keeps it compliant with energy efficiency regulations. By addressing the weaknesses found through targeted home improvements, you can increase both your home’s value and your quality of life. I recommend using the HERS rating to help you make smart decisions that save you money while protecting the environment.