Multifamily HERS Ratings, ENERGY STAR & Phius Verification in Massachusetts
HERS ratings for every unit, ENERGY STAR Multifamily New Construction and Phius multifamily verification for apartment, condo and townhouse buildings across Massachusetts. We model each unit from your plans, inspect before drywall, and blower-door and duct-test every unit with our own crew.
Built to cut your build cost
We use the options in the Massachusetts energy code to find the cheapest way for your building to pass, usually saving developers $5,000 to $10,000 per unit compared with over-building to a prescriptive spec.
Multifamily HERS Ratings in Massachusetts
Home Energy Efficiency Consultants rates multifamily buildings across Massachusetts, from 4-unit townhouses to 60-plus-unit apartment and condo buildings. We model every unit, inspect insulation and air sealing before drywall, test each unit ourselves, and deliver the HERS reports, ENERGY STAR Multifamily New Construction paperwork or Phius verification your building department and incentive programs require.
Written by Dominic Zammuto, RESNET-certified HERS Rater (#3385643) and Phius Certified Verifier, Multifamily Qualified (Phius ID 124235).
Best fit for projects like:
- New apartment and condominium buildings
- Townhouse and 3-4 unit infill buildings
- Mixed-use buildings with residential units over retail
- Office-to-residential and other change-of-use conversions
- Buildings pursuing ENERGY STAR MFNC or Mass Save incentives
- Phius Passive House multifamily buildings
Multifamily Projects We’re Working On
A sample of the multifamily buildings our team is rating and testing right now. We list projects by city and size only, to respect our clients’ privacy.
| Location | Building | What we’re doing |
|---|---|---|
| Quincy, MA | 63-unit residential building | HERS ratings for every unit under the Stretch Code (HERS 45 all-electric / 42 with fossil fuel) |
| Framingham, MA | 40-unit condominium over a heated ground-floor commercial space | Unit-by-unit HERS models, blower door testing of each unit, ERV airflow targets per unit |
| Fitchburg, MA | 24-unit all-electric building | Projected HERS ratings for all 24 units, ducted heat pumps and heat pump water heaters, duct leakage testing |
| Somerville, MA | 12 all-electric units in four buildings | HERS 45 target, per-unit ERVs, blower door targets held under 3.0 ACH50 |
| Somerville, MA | Passive House (Phius) project | Phius Certified Verifier and Rater, working alongside the project's CPHC |
| Boston, MA | Historic office-to-residential conversion | Energy-code path for a historic building and HERS ratings for Mass Save incentives |
| North Attleborough, North End (Boston), Hyde Park | 4-unit townhouse and condo buildings | All-electric HERS ratings from plan review through final testing |
Which Energy Code Path Does Your Multifamily Building Need?
The answer depends on your town’s code tier and the building’s size. We tell you before you finish design.
Does every unit need a HERS rating?
For new multifamily buildings that follow the HERS (ERI) path of the Massachusetts Stretch Energy Code, yes. Each dwelling unit gets its own HERS rating and its own blower door test, and each unit must meet the target: HERS 42 with fossil fuel equipment or HERS 45 all-electric.
When is Passive House required?
In towns that adopted the Specialized (Opt-In) Energy Code, new multifamily buildings over 12,000 square feet must be certified to Passive House, which in practice means Phius verification. In Stretch Code towns such as Quincy, a large multifamily building can comply with HERS ratings alone.
Renovations and change of use
Gut renovations and change-of-use projects that need a HERS rating target HERS 65 with gas and HERS 70 all-electric. Historic buildings can have exceptions, so we check the code path before anything is designed.
Where the savings come from
Blower door results, ERV sizing, window specs and insulation levels all trade off against each other in the HERS model. Picking the right mix is how we usually save $5,000 to $10,000 per unit.
Multifamily Buildings Over 12,000 Sq Ft: Passive House Certification & CPHC Design
In Massachusetts towns on the Specialized (Opt-In) Energy Code, a new multifamily building over 12,000 square feet has to be built and certified to Passive House. We handle both sides of that under one roof: the CPHC design work and the Phius verification.
CPHC Passive House design
Our Certified Passive House Consultant (CPHC) models the building, sets the wall, roof, window and ventilation specs, and works with your architect and MEP engineer so the design meets the Passive House targets before you go to permit.
Phius certification & verification
Dominic is a Phius Certified Rater and Phius Certified Verifier, Multifamily Qualified (Phius ID 124235). We do the construction inspections, the airtightness and ventilation testing, and the paperwork Phius needs to certify the building.
Is your building over the line?
Whether a project crosses 12,000 sq ft, and whether the town is on the Specialized code, decides if you need Passive House or can comply with HERS ratings. We work it out with your building department early, before the design is locked in.
Under 12,000 sq ft or a Stretch Code town?
Then HERS ratings for every unit are usually the path (HERS 42 fossil fuel / 45 all-electric), and ENERGY STAR or Passive House stay optional upgrades that can earn larger Mass Save incentives.
See Phius Passive House verification, Phius certification cost and which towns are on the Specialized code.
ENERGY STAR Multifamily New Construction (MFNC) in Massachusetts
ENERGY STAR Multifamily New Construction has three ways to certify: the ERI (HERS) path, the ASHRAE 90.1 performance path, and the prescriptive path. For most low- and mid-rise Massachusetts buildings we use the ERI path, because the same unit models that prove Stretch Code compliance can carry the ENERGY STAR certification and unlock larger Mass Save new construction incentives.
Dominic completed the ENERGY STAR Multifamily New Construction rater training, RESNET’s Multifamily High-Rise training and DOE Efficient New Homes Multifamily v2. See our ENERGY STAR certification page and Mass Save new construction incentives.
How a Multifamily HERS Rating Works With Us
Four steps from your permit set to final certificates, with the same team on every visit.
Plan review & projected ratings
We model every unit from your architectural and mechanical plans and show you the cheapest combination of insulation, windows and equipment that hits the target.
Pre-drywall inspection
We inspect insulation and air sealing in every unit before drywall, so problems are fixed while they’re cheap.
Unit testing
Blower door testing of each unit, duct leakage testing and ERV/HRV airflow verification, all by our own crew.
Final ratings & paperwork
Final HERS certificates for the building department, plus ENERGY STAR, Mass Save or Phius documentation where it applies.
How Much Does a Multifamily HERS Rating Cost?
Multifamily HERS ratings run $900 to $1,450 per unit in 2026, depending on unit count, how many unit types repeat, and the number of site visits. Larger buildings with repeated floor plans come in at the lower end. Use the HERS rating cost calculator or call 617-501-6788 for a quote on your building.
Multifamily Credentials
- RESNET-certified HERS Rater, RESNET ID 3385643
- Phius Certified Rater and Phius Certified Verifier, Multifamily Qualified, Phius ID 124235
- ENERGY STAR residential rating partner; ENERGY STAR Multifamily New Construction rater training
- U.S. DOE Efficient New Homes partner (org ID 4379); EPA Indoor airPLUS and WaterSense verifier
- Listed on Mass Save’s certified HERS rater list for Residential New Construction
- 25+ years in construction; four offices in Somerville, Framingham, Everett and Marlborough
Our Massachusetts Service Locations
Serving clients from our four Massachusetts locations in Everett, Somerville, Framingham, and Marlborough.
Everett Location
371 Main St
Everett, MA 02149
Somerville Location
519 Broadway
Somerville, MA 02145
Framingham Location
68 South St
Framingham, MA 01702
Marlborough Location
272 Lincoln St, C1
Marlborough, MA 01752
Related Multifamily Services
ENERGY STAR Certification
Single-family and Multifamily New Construction certification statewide.
Phius Passive House Verification
Multifamily-qualified Phius Rater and Verifier for Specialized-code projects.
Blower Door Testing
Unit-by-unit airtightness testing to the 3.0 ACH50 code limit.
ERV Requirements
Balanced ventilation sizing and airflow testing for every unit.
Office-to-Residential Conversions
Energy code paths for change-of-use buildings in Boston and statewide.
Specialized (Opt-In) Code
Which towns require all-electric, solar or Passive House.
Multifamily HERS Rating FAQ
Common questions from Massachusetts developers, builders and architects.
Can you do both the Passive House design and the Phius certification for a multifamily building over 12,000 sq ft?
Yes. Our Certified Passive House Consultant (CPHC) handles the Passive House design and energy modeling, and Dominic Zammuto, a Phius Certified Rater and Verifier with the Multifamily qualification (Phius ID 124235), does the inspections, testing and Phius verification.
Does every unit in a Massachusetts multifamily building need a HERS rating?
For new multifamily buildings on the HERS (ERI) path of the Massachusetts Stretch Energy Code, each dwelling unit gets its own HERS rating and blower door test and must meet the target: HERS 42 with fossil fuel or HERS 45 all-electric for new construction.
When does a multifamily building in Massachusetts need Passive House?
In towns that adopted the Specialized (Opt-In) Energy Code, new multifamily buildings over 12,000 square feet must be Passive House certified, usually through Phius. In Stretch Code towns a large multifamily building can comply with HERS ratings alone.
How much does a multifamily HERS rating cost in Massachusetts?
Multifamily HERS ratings from Home Energy Efficiency Consultants run $900 to $1,450 per unit in 2026, depending on unit count, repeated unit types and the number of site visits.
Which ENERGY STAR Multifamily New Construction path should my building use?
ENERGY STAR MFNC can be certified through the ERI (HERS) path, the ASHRAE 90.1 performance path or the prescriptive path. Most low- and mid-rise Massachusetts buildings use the ERI path because the unit HERS models already needed for code compliance carry the certification.
Do you test every unit yourselves?
Yes. Our own crew does the pre-drywall inspections, blower door testing of each unit, duct leakage testing and ERV/HRV airflow verification. We don't subcontract testing.
How can a HERS rating lower the cost of a multifamily building?
The HERS model lets you trade insulation, windows, airtightness and equipment against each other. Finding the cheapest combination that passes usually saves developers $5,000 to $10,000 per unit compared with over-building to a prescriptive spec.
Planning a Multifamily Building in Massachusetts?
Send your plans and we’ll tell you the code path, the HERS targets and where you can save money.
Mass Save®-Listed HERS Rater
U.S. DOE Efficient New HomeTrusted Partner — Verified
ENERGY STAR®Partner
Phius CertifiedPassive House Verifier
ICCMember★★★★★136 Google
Reviews
The Phius Certified Verifier logo is used under license from Phius.
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