WHAT IS A HERS RATING?

HERS stands for Home Energy Rating System, which is the industry standard for measuring the energy efficiency of a home. It provides a holistic view of the home’s energy usage, including performance testing, building materials, HVAC systems, appliances, and lighting. The HERS rating is one of the most commonly used methods to demonstrate compliance with local energy codes, particularly in Stretch Code communities, where a HERS score of 42 or less (for mixed-fuel buildings) or 45 or less (for all-electric buildings) is required.

A great HERS Rater is key to a smooth path toward energy code compliance. Achieving a high HERS score can also qualify a home for valuable incentives, including utility incentive programs, $2000 45L tax credits, and certifications such as Passive House, ENERGY STAR, and LEED.

PERFORMANCE TESTING

We perform a comprehensive suite of performance tests to measure the efficiency of your home’s systems. These non-invasive tests include:

• Blower Door Test: Measures airtightness to assess heat loss and efficiency.
• Duct Test: Assesses the efficiency of your ductwork (if present).
• Ventilation Test: Verifies the effectiveness of your home’s ventilation systems.

The results from these tests are input into a HERS rating software to help calculate the home’s overall energy performance.
To learn more, check out our article – “Performance Testing.”

BUILDING MATERIALS

A HERS rating takes into account various building materials, including:

• Insulation: The type, depth, and quality of insulation are critical for calculating the R-Value of walls, floors, and ceilings.
• Windows: Performance ratings of windows, including U-Value and Solar Heat Gain Coefficient (SHGC), are documented.
• Other Factors: The framing factor of walls and the presence of radiant barriers on the roof are also considered when calculating the HERS score.

HVAC

The heating, cooling, and domestic hot water systems (DHW) are thoroughly documented. We assess:

• Type: The fuel type (gas, electric, etc.) and size of the system.
• Efficiency: We evaluate how efficiently the system operates.
• Distribution: For DHW, we check features like pipe insulation and total system length.
• Ventilation Systems: Ensuring the HVAC and ventilation systems meet all applicable building codes.

APPLIANCES & LIGHTING

The type and efficiency of appliances and lighting can affect your HERS score. We will evaluate:

• Appliances: Items like refrigerators, dishwashers, ranges, washers, and dryers are assessed. If these items aren’t part of your project, default settings can be used, though most modern appliances exceed the default efficiency standards.
• Lighting: We check whether lighting is high-efficiency LED, compact fluorescent, or incandescent.

OUR PROCESS

1. Plans Review + Energy Modeling
   Once we receive your project plans, we create an energy model of your project using software to predict energy performance. We then produce a preliminary HERS certificate, which is required to obtain your building permit. Depending on your budget and performance goals, we may:

   • Suggest cost-effective strategies to ensure code compliance.
   • Perform a “what-if analysis” (value engineering) to help you get the best return on your investment.
   • Explore Net Zero energy options.

2. Energy Consulting + Midpoint Inspection
   During the construction process, we help you identify potential weak points early on. After the insulation work is completed, we perform an on-site visit to ensure that the project is aligned with the local energy code requirements. We provide recommendations to resolve any issues before they become costly problems.

3. Final Inspection
   As your project nears completion, we conduct a final inspection and perform the necessary tests (blower door test, duct leakage test, and ventilation test). We then issue a final HERS certificate, which is required to obtain your Certificate of Occupancy. If your project qualifies, we can enroll it into the applicable Mass Save incentive program and take care of all the paperwork to maximize the incentives available to you.