The Home Energy Rating System (HERS) score is a nationally recognized standard that measures a home’s energy efficiency. Think of it like a miles-per-gallon rating, but for your home. The lower the score, the more energy-efficient the home is. This rating plays a crucial role in helping homebuyers, builders, and real estate agents understand how a home will perform in terms of energy use, comfort, and utility costs.
At Total Quality Home Builders, energy performance is one of our top priorities. Every custom home we design is built with modern energy efficiency practices in mind. Understanding the HERS rating helps our clients make informed decisions about the design, materials, and features of their home.
Key Highlights
- HERS stands for Home Energy Rating System and is a trusted standard for measuring residential energy efficiency across the United States. It works like a “miles per gallon” rating for homes, giving buyers and builders an apples-to-apples comparison of energy performance.
- The HERS rating is developed by RESNET and calculated by certified raters using on-site inspections, performance testing, and energy modeling. The score reflects how well the home conserves energy, with lower scores representing better efficiency and greater long-term savings.
- A HERS score of 100 represents a standard new home built to 2006 energy codes, while a score of 0 indicates a net-zero energy home that produces as much energy as it consumes. Most energy-efficient custom homes fall between 50 and 70 on the scale.
- The HERS score affects real-world factors such as utility bills, indoor comfort, air quality, and resale value. A low score indicates reduced energy waste, smaller carbon footprint, and improved overall living conditions, making it an essential benchmark for eco-conscious homeowners.
How Does the HERS Rating Work?
Understanding how a HERS rating is calculated can provide a better understanding of your home’s energy performance and identify where improvements can make the most significant difference. The process is highly structured and data-driven, relying on a combination of physical inspections and computer modeling. A certified HERS rater evaluates your home’s energy systems, construction quality, and air flow performance. The rater then compares it against a standardized reference home, producing a clear, measurable score that reflects how efficiently your home uses energy.
Understanding the Scoring System
The HERS rating is calculated by a certified HERS rater using standardized testing procedures. The rating compares a tested home to a reference home built to 2006 energy efficiency standards.
- Score of 100: Represents the baseline. Equivalent to a home built to 2006 energy codes.
- Score of 0: Indicates a net-zero energy home, meaning the home produces as much energy as it consumes.
- Each point above 100: Means the home is less efficient.
- Each point below 100: Means the home is more efficient.
A typical resale home in the U.S. scores around 130. A newly built energy-efficient custom home may fall between 50 and 70.
HERS Rating Chart
To help visualize how different homes compare in terms of energy efficiency, the HERS rating chart breaks down standard score ranges. This quick reference provides a clear understanding of what each score typically means in real-world terms, ranging from older resale homes to high-performance custom builds.
| HERS Score | Energy Efficiency | Type of Home |
| 130 | Poor | Older resale home |
| 100 | Standard | 2006 code-built home |
| 70 | Good | New energy-efficient home |
| 50 | Excellent | High-performance custom home |
| 0 | Net-Zero | Produces as much as it uses |
Why the HERS Rating Matters
A HERS score isn’t just a technical metric. The score affects real-world aspects of homeownership that matter every day. From energy costs to indoor comfort to environmental impact, the HERS rating gives homeowners a clear, measurable way to assess how well their home performs. Whether you’re focused on saving money, reducing your carbon footprint, or simply living in a more comfortable space, understanding why this rating matters can guide smarter decisions during the custom home-building process.
Lower Utility Costs
Homes with lower HERS scores consume less energy, resulting in lower monthly utility bills. Over time, that translates to significant savings. For homeowners building a custom home, these savings can free up budget for additional design upgrades or future investments. A lower score also protects against rising utility rates, making your home more cost-effective in the long term.
Greater Comfort and Health
Energy-efficient homes are better sealed and insulated, meaning more consistent indoor temperatures, fewer drafts, and improved indoor air quality. Sealed ductwork and high-efficiency HVAC systems help reduce allergens and pollutants, making them especially beneficial for families with asthma, allergies, or other respiratory conditions. Comfort isn’t just about the thermostat; it’s also about reducing noise, odors, and humidity swings that affect daily life.
Environmental Impact
Homes with better HERS ratings use less energy from fossil fuels, reducing carbon emissions. A low HERS score helps minimize your home’s contribution to greenhouse gases and supports broader environmental goals. If sustainability is important to you, the HERS rating provides a concrete and measurable way to act on those priorities. It’s also worth noting that energy-efficient homes typically use fewer resources over their lifetime, making them a smarter long-term investment for the planet.
What Goes into a HERS Rating?
A certified HERS rater inspects and tests a variety of home features, including:
- Insulation levels and installation quality – The type, amount, and proper installation of insulation significantly impact how well a home retains heat and cooling. Poorly installed insulation can lead to energy loss, even if the material itself is highly rated.
- Air leakage (blower door test) – A blower door test measures how much air is escaping from or entering the home through gaps, cracks, or other openings. A tightly sealed building envelope helps reduce energy consumption.
- Duct leakage – Leaky ductwork wastes heated or cooled air before it reaches the rooms where it’s needed. A duct leakage test identifies these inefficiencies, allowing them to be sealed or corrected.
- HVAC system performance – The efficiency and proper sizing of heating and cooling systems significantly impact a home’s energy use. A well-designed system will run less often and use less energy.
- Windows and doors – The type of windows and doors, their thermal performance, and how well they’re sealed all influence the home’s overall energy efficiency. High-performance windows can prevent heat loss and solar gain.
- Water heating system – Water heaters are one of the biggest energy consumers in a home. The rater examines the energy factor, size, and placement of the system to evaluate its efficiency.
- Lighting and appliances – Energy-efficient lighting and ENERGY STAR-certified appliances reduce a home’s electrical load. These components are factored into the total energy consumption model.
Each element contributes to the final HERS score. The rater uses software to model the home’s expected energy use, comparing it to the reference standard.
HERS Rating vs. Energy Star Certification
While both the HERS rating and Energy Star certification focus on home energy efficiency, they serve slightly different purposes. The HERS rating is a numerical score that enables detailed comparisons between homes, whereas Energy Star certification is a pass/fail system based on specific performance benchmarks. Understanding how these systems differ and how they complement each other can help you make better choices when planning your custom home’s energy strategy.
| Feature | HERS Rating | Energy Star Certified Homes |
| Who provides it? | RESNET | U.S. Environmental Protection Agency |
| Type | Numeric score | Certification label |
| Flexibility | More granular measurement | Must meet specific criteria |
| Customization | Can reflect custom designs | Based on set benchmarks |
| Widely used for | New and existing homes | New construction only |
Both systems work together. An Energy Star-certified home typically has a HERS score of 60 or lower.
Frequently Asked Questions about HERS Ratings
Is a HERS rating required?
In many regions, a HERS rating is not legally required; however, it is increasingly used as a means to comply with local or state energy codes. Some municipalities mandate a certain HERS score for new construction or major renovations. Even where it’s not required, a HERS score provides a valuable benchmark for energy performance, helping builders and homeowners identify areas for improvement. South Carolina has adopted the 2009 IECC with amendments; however, many builders go beyond the code by pursuing better HERS scores.
Can an older home get a HERS rating?
Yes. A HERS rater can evaluate any home, new or existing. Rating an older home can be a helpful step in planning energy efficiency upgrades. The rating process will identify where the home is losing energy, and the final report often includes recommendations to improve insulation, upgrade HVAC systems, and seal air leaks. It’s a smart move for homeowners seeking to enhance comfort and lower their utility costs.
How much does a HERS rating cost?
The cost of a HERS rating depends on the size and complexity of the home, local market rates, and whether the home is a new build or an existing one. Costs vary depending on the size and location of the home. In South Carolina, the average cost typically ranges from $500 to $1,200.
Will a lower HERS score increase my home’s value?
Yes, especially as buyers become more conscious of energy efficiency and long-term costs. A home with a lower HERS score generally has lower operating expenses, which is appealing to cost-savvy homebuyers. Some studies even suggest that homes with better energy ratings sell faster and at a higher price. In addition, green mortgages and energy-efficient financing options often favor homes with low HERS scores.
Building an Energy-Efficient Custom Home
A great HERS score starts with thoughtful design. Our team utilizes high-quality materials and innovative building practices to craft homes that not only look beautiful but also perform exceptionally well.
We begin by assessing the site orientation, window placement, and insulation requirements to reduce heating and cooling loads. Our architects and builders work together to integrate advanced framing techniques, high-performance HVAC systems, and tightly sealed building envelopes.
Next, we select energy-efficient features and materials, such as:
- ENERGY STAR-rated windows and appliances
- Spray foam or blown-in insulation for maximum thermal performance
- High-efficiency HVAC units with programmable thermostats
- LED lighting throughout the home
- Tankless or heat pump water heaters
We also consider renewable energy options, such as solar panels, for clients seeking to reduce their HERS score further or transition toward a net-zero design.
Finally, we coordinate with certified HERS raters during the final construction phases to ensure that every element has been properly implemented. If anything needs adjustment, we handle it before move-in, so the home is fully optimized from day one.
Ready to Build a Smarter, More Efficient Home?
At Total Quality Home Builders, we combine high-end design with proven energy-saving strategies to create homes that are both stylish and efficient. Want a home that performs as beautifully as it looks? Contact us today to start planning your energy-efficient custom home.
Looking for more energy tips? Visit our Custom Home Building Process page to learn how we bring every detail together.
