Every day, more homeowners are making the decision to prioritize energy efficiency in their home selection process. It’s no longer the case that efficiency is seen simply as a trendy style choice or millennial fad. Instead, energy efficiency can save new homeowners a significant expense, both in the immediate and long term, if they choose to shop wisely.
Any homeowner looking for ways to decrease costs and increase comfort in their home can start by measuring their home’s efficiency and identifying areas for improvement. Once you know how your home compares to others of similar size and build, you will have a sense of how it is performing and can take steps to improve its efficiency. The best way to measure your home’s efficiency is by using the Home Energy Rating System, or HERS index.
The Home Energy Rating System
A home’s energy performance is measured using the HERS index, also seen as the industry’s gold standard for efficiency rating. As a nationally recognized measurement, HERS is the acronym for Home Energy Rating System. It was launched in 2006 by the Residential Energy Services Network (RESNET) and continues to be widely recognized by home professionals as a reliable and consistent barometer.
More importantly, what does this mean for new homebuyers? Generally, the lower your home’s HERS score, the greater its efficiency. In this case, you WANT to score as low as possible, and in return you get to enjoy the ease of comfortability and reduction in monthly energy costs. For sellers, a low rating can increase the value of your home and help you to earn a little bit more upon resale.
Getting a HERS Rating
Homes must go through an intensive process to receive a HERS score. It must be inspected by a certified RESNET rater using their official equipment. An inspection and assessment may cost $1,500 – $3,000, which is no small change. However, getting a HERS score can save homeowners money if they make the suggested energy improvements.
What Variables are Considered in a HERS Rating?
Certified raters will perform a comprehensive evaluation on your home to better understand its energy consumption and clean energy production. A few variables that go into an energy rating are in the home’s structure (all above and below grade exterior walls, insulation, ceilings, flooring, roofs, attics, and foundations), access points/exits (windows and doors, vents, ductwork), and major systems (HVAC, water heater, thermostat, appliances). Any alternative energy sources will also be considered, such as solar panels.
What do the Scores Mean?
The HERS index is calculated by a certified rater using specialized software that compares your home to a standard Reference Home with a score of 100. The Reference Home is not an actual house, but it represents a baseline for one that is similar to yours in size, shape, location, and environment. In effect, your score is relative to the type of house you own.
Using the Reference Home as an analysis tool, a score of 100 represents a standard new conventional house. A point up or down indicates a one percent shift in energy efficiency from the baseline. So, a home with a score of 120 operates at 20 percent more energy than the standard new home of similar characteristics while a house with a score of 80 uses 20 percent less energy than the standard.
In general, scores above 100 consume more energy while scores lower than 100 use less, thus making them more energy efficient. Here’s a rough outline of what your home’s score may indicate.
Significant Issues (150+)
A HERS score of 150 indicates that the home uses 50 percent more energy than a standard new home built to code. Many older homes that score higher than 150 or 200 may create a significant financial strain on your bank account for less comfort and a negative impact on the environment.
Standard Resale Home (130)
A score of 130 is typical for a standard resale home or lived-in house. This is considered a generally good score, but you could make a few improvements here or there if you want to improve efficiency.
Standard New Home Built to Code (100)
While a HERS rating of 100 is the industry standard for a new home, it does not mean that the home is considered energy efficient by a green building standard, but it does meet the standard code. This is the lowest acceptable level of efficiency permitted by code.
Energy Efficient Home (85 or lower)
A HERS score of 85 or lower is considered an energy efficient home. The lower the score, the more annual energy savings you may be earning. Homes in this range may be eligible for ENERGY STAR certification status if they meet the target score and satisfy other requirements.
Net Zero Energy Home (0)
Homes that produce or conserve as much energy as they use are considered a “net-zero” home and earn a HERS score of 0. Very few homes earn this score as they generally require some form of alternative energy generation, such as wind or solar. For homeowners who love to maximize efficiency, achieving a net-zero home is a brilliant way to dramatically reduce your carbon footprint while saving thousands of dollars on energy costs.
Positive Energy Home (-1 or lower)
A negative HERS rating is actually referred to as a “Positive Energy Home.” Yep, you read that right! A home that is more efficient than a net zero home generates more clean energy than is used to maintain the home. Each negative point indicates one percent of the energy that a standard new home would require being returned to the grid. For example, a HERS rating of -10 means the home produces 10 percent more clean energy than a standard new home would use.
What’s Hurting my HERS Score?
One of the biggest energy drains in a home can be traced to air leaks. Any leaks through the exterior walls or attic that allow heat to escape will cause your HVAC system to work harder and decrease efficiency. High-power appliances that are constantly running may also contribute to a higher score.
How Can I Improve my HERS Score?
When you obtain your home’s official HERS rating from a certified rater, you will also receive a detailed report with recommendations for improving your score. Raters often provide a cost/benefit analysis for any recommended upgrades to show homeowners how much they can save in the long run by making their home even slightly more efficient.
The Benefits of a Good HERS Score
Learning your new home’s HERS rating early on can help you budget for utility expenses, as it will provide you with an accurate financial picture of the home’s long term costs. If you take the time to look for a home with a good HERS score and invest a little extra money initially, it may save you thousands over the years in utility costs, repairs, and efficiency upgrades.
A good HERS score is an excellent selling point for any resale home. Outstanding energy efficiency and a low HERS score may even increase your home’s resale price. Research by NerdWallet indicates that upgrading a home’s energy efficiency by installing better insulation, system appliances, and windows may increase a home’s appraisal by two to six percent. That money means a smaller carbon footprint and happier bank account.
The RESNET National Rating Registry
If you are interested in additional resources or want to get in touch with a certified rater in your area, check out the resources below.
Find a HERS Rated Home
For energy-conscious homeowners searching for a new home that is efficient, comfortable, and results in lower energy bills, RESNET HERS Index Score Information is a great place to start. You can view details on any HERS rated home before even scheduling a showing!
Find a Certified HERS Rater
To get in touch with a certified HERS Rater or verify the credentials of a local rating company, visit RESNET National Registry.
Getting your Home HERS-ready
Before scheduling an evaluation, you can put your best foot forward by doing a thorough sweep of your home for any gaps in the siding or around windows and doors. Use either caulk or high-quality tape to seal any gaps you find that allow air to seep in or out of the home. Adding weather stripping to windows and doors will also be beneficial.
Adding or repairing insulation will also prevent excessive heat transfer. Don’t forget to check the basement and the attic, which likely have many holes for wiring and system pipes that may need insulation. If nothing else, you can reduce your utility bills by adjusting your thermostat five to 10 degrees.
These are just a few ways to get started on lowering your HERS score and maintaining a healthy level of energy efficiency. Your bank account (and carbon footprint!) will thank you for taking the next step towards a more comfortable, efficient, and environmentally friendly home.
Melanie Theriault is a writer, counselor, and lifelong learner. She holds a B.A. in Sociology from Southwestern University, where she discovered her passion for fostering human connection through storytelling.