Hers Index Calculator

The Home Energy Rating System (HERS) Index is a scoring system used to measure a home’s energy efficiency. A lower HERS Index Score indicates a more energy-efficient home. Using a HERS Index Calculator can help homeowners and builders understand and improve the energy performance of a property.

Importance of a HERS Index Calculator

Understanding a home’s HERS Index Score is crucial for several reasons:

  • Energy Efficiency: A lower score means the home is more energy-efficient, which can lead to lower energy bills.
  • Environmental Impact: Energy-efficient homes contribute less to greenhouse gas emissions.
  • Market Value: Homes with better energy ratings are often more attractive to buyers and can have higher market values.
  • Informed Decisions: Knowing the HERS Index Score helps homeowners make informed decisions about energy upgrades and improvements.

How to Use a HERS Index Calculator

  1. Reference Home Energy Consumption: Enter the energy consumption of a standard reference home in BTUs.
  2. Rated Home Energy Consumption: Input the actual energy consumption of the rated home in BTUs.
  3. Calculate the Score: Click the calculate button to determine the HERS Index Score.
  4. View Results: The calculator will display the HERS Index Score, indicating the energy efficiency of the home.

10 FAQs about the HERS Index Calculator

1. What is the HERS Index?

  • The HERS Index is a scoring system for measuring a home’s energy efficiency, with lower scores indicating higher efficiency.

2. How is the HERS Index Score calculated?

  • The score is calculated using the formula: HERS Index Score=Reference Home Energy Consumption−Rated Home Energy ConsumptionReference Home Energy Consumption×100\text{HERS Index Score} = \frac{\text{Reference Home Energy Consumption} – \text{Rated Home Energy Consumption}}{\text{Reference Home Energy Consumption}} \times 100HERS Index Score=Reference Home Energy ConsumptionReference Home Energy Consumption−Rated Home Energy Consumption​×100.

3. Why is a lower HERS Index Score better?

  • A lower score indicates that the home is more energy-efficient and uses less energy compared to a standard reference home.

4. What is a good HERS Index Score?

  • A typical new home scores around 100, while an energy-efficient home can score 70 or lower. A net-zero energy home scores 0.

5. Can older homes achieve a low HERS Index Score?

  • Yes, with energy-efficient upgrades and renovations, older homes can significantly lower their HERS Index Score.

6. How does the HERS Index affect home value?

  • Homes with better energy ratings are often more desirable and can have higher market values due to lower operating costs and environmental benefits.

7. Is the HERS Index used for all types of homes?

  • Yes, the HERS Index can be used to evaluate single-family homes, multifamily units, and even commercial buildings.

8. What factors can improve a HERS Index Score?

  • Improving insulation, installing energy-efficient windows and appliances, and sealing air leaks can all contribute to a better score.

9. Who conducts HERS Index ratings?

  • Certified HERS raters conduct assessments, using specialized equipment and software to evaluate a home’s energy performance.

10. Is a HERS Index Score required for new homes?

  • In some regions and for certain programs, a HERS Index Score is required to meet energy efficiency standards and qualify for incentives.


Understanding and utilizing a HERS Index Calculator is essential for homeowners and builders looking to improve energy efficiency. By calculating the HERS Index Score, you can make informed decisions about energy upgrades, reduce environmental impact, and potentially increase the value of your property. Embrace the power of energy efficiency and take the first step towards a greener, more cost-effective home.