Planning a Renovation? What You Need to Know About HERS Ratings in Massachusetts
Introduction
If you’re planning a renovation or addition in Massachusetts, you may be surprised to learn that your project could trigger a HERS Rating requirement. Unlike new construction, where everything is built to today’s energy code, renovations come with a unique challenge: the entire home must meet the required HERS score—even the parts that aren’t being touched.
That means older windows, outdated heating systems, or walls that can’t be opened for new insulation are still part of the equation. Understanding this early can save you headaches, delays, and unexpected costs.
Why This Matters for Renovations
When a major renovation or addition falls under the MA Stretch Code or Specialized Opt-In Code, it’s not just the new square footage that gets evaluated. The whole home is tested and modeled for energy performance.
For many homeowners, this is where surprises happen. That charming original window package, the 20-year-old furnace, or the poorly insulated walls left intact can all lower the final HERS score—making compliance harder to achieve.
Common Challenges Homeowners Face
Renovations often blend new high-performance construction with existing older systems, which can create gaps:
Windows & doors: Single- or double-pane originals can drag down efficiency.
HVAC systems: Outdated or oversized systems increase energy use.
Walls: If not opened during renovation, insulation upgrades are limited.
Air leakage: Older framing and assemblies typically leak more than new builds.
Each of these factors plays into the final HERS model and blower door test results.
Setting Realistic Expectations
Because the entire home must comply, homeowners should prepare for the possibility of unplanned upgrades. This doesn’t mean your project is doomed—just that flexibility may be required.
For example, you might need to:
Replace older windows sooner than planned.
Upgrade an inefficient heating system.
Add insulation or air sealing to existing walls, attics, or basements.
These adjustments ensure compliance and improve the long-term performance of the home.
Tips for a Successful Renovation HERS Rating
The good news: with the right planning, you can pass without costly surprises.
Engage a HERS rater early in the design process.
Ask for scenario modeling to see which upgrades deliver the biggest impact.
Focus on air sealing—especially where new and old construction meet.
Consider HVAC upgrades, even if your existing system still runs.
Explore solar PV or other renewable energy to offset performance gaps.
These strategies not only improve compliance but also lead to a more efficient and comfortable home.
The Upside: Long-Term Benefits
While the need for additional upgrades may feel frustrating in the short term, the payoff is worth it:
Lower utility bills year after year
Improved comfort across all seasons
Higher resale value with documented energy efficiency
Code compliance without delays at final inspection
By thinking about energy performance during design, you avoid last-minute surprises and end up with a better-performing home.
FAQ: What Happens if I Don’t Meet the HERS Score?
If your home doesn’t meet the required HERS score, you can’t pass energy code—and that can hold up your occupancy permit. In most cases, this means additional work like air sealing improvements, insulation upgrades, or mechanical changes to bring the score into compliance.
Working with a HERS rater early minimizes this risk and helps you plan upgrades strategically.
Conclusion
Renovations in Massachusetts bring unique challenges when it comes to energy code compliance. The key takeaway: a HERS Rating covers the entire home, not just the new addition. By planning ahead, working with a rater early, and preparing for possible upgrades, you’ll ensure a smoother path to compliance and a more efficient home for the long run.
👉 Ready to plan your renovation with confidence? Contact us today to learn how Spectrum Energy can guide your project to HERS compliance.
