The Performance Path vs. The Prescriptive Path

Performance Path Compliance

• Requires energy modeling to demonstrate that the overall energy performance of the building is at least as efficient as the prescriptive path.
• Offers more flexibility, allowing builders to “trade off” high-cost items to achieve compliance, making it more cost-effective in many cases.
• Often includes HERS Ratings, a common method for achieving the Energy Rating Index (ERI) and verifying energy efficiency.

Prescriptive Path Compliance

• Involves following specific component values for insulation, windows, and HVAC systems as detailed in the IECC.
• Less flexible than the performance path, but may be simpler to follow for smaller or more standard buildings.
• Requires performance testing such as blower door tests and duct leakage tests to confirm the airtightness and efficiency of the building.

What is the Stretch Energy Code?

The Massachusetts Stretch Energy Code is an appendix to the base energy code that sets even higher standards for energy efficiency. Initially adopted in 2009, the Stretch Code encourages cost-effective building practices that exceed the standard IECC requirements, resulting in buildings that are even more energy-efficient.

Key Highlights of the Stretch Code:

• Emphasizes energy performance rather than just prescriptive requirements.
• Targets a 50% reduction in energy use compared to typical buildings built under the standard base energy code.
• Requires additional air sealing, insulation, and energy modeling to ensure optimal performance.

New Changes to the Stretch Code in 2023

Massachusetts updated its Stretch Code in 2023, incorporating new requirements for residential buildings (3 stories or less). Some important changes include:

• Higher HERS Ratings:
  • HERS 42 for mixed-fuel buildings.
  • HERS 45 for all-electric buildings, which can qualify for additional incentives.
  • HERS 45 for mixed-fuel buildings with solar electric generation.
• Energy Ventilation:
  • ERV/HRV (Energy Recovery Ventilator/Heat Recovery Ventilator) systems will be required for whole-house ventilation.
  • Bath fans will no longer meet ventilation requirements.
• Electric Vehicle (EV) Readiness:
  • One EV-ready space and wiring will be required per house, with additional requirements for multi-family projects.
• HVAC Duct Leakage Testing:
  • Now required for all systems, even if the ducts are located inside the conditioned envelope.

Why is Compliance So Important?

1. Energy Efficiency: Ensuring that your building meets the latest energy code standards reduces energy consumption and helps lower utility costs for the lifetime of the building.
2. Financial Incentives: Compliance with the 2018 IECC and Stretch Code can make your project eligible for a variety of financial incentives, including Mass Save rebates, 45L Tax Credits, and other energy efficiency programs.
3. Sustainability: Meeting or exceeding energy codes is crucial to reducing a building’s environmental impact, decreasing carbon emissions, and supporting a more sustainable future.
4. Market Appeal: Energy-efficient homes are highly desirable in today’s market, making them more attractive to potential buyers and increasing resale value.

How We Can Help

At HERS Rating Specialist, we offer comprehensive services to ensure your project complies with both the 2018 IECC and the Stretch Code. Our team of certified experts will guide you through the entire process:

• Energy Modeling & Compliance Path Selection: We help determine which compliance path (performance or prescriptive) is right for your project.
• Testing & Inspections: We provide all necessary testing, including blower door and duct leakage tests, to verify compliance.
• HERS Rating: We offer comprehensive HERS ratings to evaluate and certify the energy performance of your building.
• Incentive Enrollment: We assist in enrolling your project in available incentive programs, maximizing potential savings.

Schedule Your Consultation

Ensure your building project complies with the 2018 IECC and Stretch Code. Contact HERS Rating Specialist today to schedule a consultation or to get started on the compliance process. Let us help you make your building energy-efficient, sustainable, and cost-effective.