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Solar site surveys · MassachusettsA technician on the roof, in the attic and at the service panel, with the survey read against the code editions, AHJs and utilities that apply in Massachusetts.
Massachusetts sets its codes statewide: the 10th edition of 780 CMR (based on the 2021 I-Codes), the Massachusetts Electrical Code, which moved to the 2026 NEC on April 24, 2026, and a fire code based on NFPA 1 that sets rooftop PV pathways. Every city and town has its own building commissioner, and 60 municipalities, including Boston, use the Specialized energy code. Most homes net meter at close to retail value, with SMART 3.0 incentives on top; surveys should plan for 40 psf-class snow loads around Boston.
The capture spec is the same everywhere. What the engineer and the plan reviewer read it against is not.
The Massachusetts Residential Code lists design values town by town. Boston's ground snow load is 40 psf with a 30 psf minimum flat-roof snow load, and inland and higher towns can be higher.6
The same residential table gives Boston a 120 mph ultimate design wind speed. Coastal towns may also fall in wind-borne debris regions, so take the value for the specific town.6
The NFPA 1-based fire code requires gutter-to-ridge pathways and ridge setbacks on one- and two-family homes, which often rules out full coverage of small or cut-up roof planes.8
Who reviews the plan set, and what the state layers on top.
Net metering under DPU rules applies to customers of the three regulated utilities (Eversource, National Grid and Unitil). Forty-one municipal light plants serve all or part of 50 communities and set their own rates, so check the address.15,16
Delivers electricity in Boston. Listed inverter-based systems of 25 kW AC or less can use the Simplified process in PowerClerk, with no application fee on radial circuits; area-network locations have tighter size limits and a fee.17,18
Interconnection page ↗Under its interconnection tariff (M.D.P.U. No. 1579, effective April 15, 2025), the Simplified process covers listed single-phase inverter systems of 15 kW or less and three-phase systems of 25 kW or less on radial circuits. Network locations are limited to 1/15 of the customer's minimum load.19
Interconnection page ↗One standard, one visit, the same record in Massachusetts as everywhere else. What it gets checked against is the code stack above.
The 2026 NEC, as amended by 527 CMR 12.00, for electrical permits applied for on or after April 24, 2026. Before that date, Massachusetts used an edition based on the 2023 NEC.1,3
Under 527 CMR 1.00 (NFPA 1, 2021), homes need two 36-inch gutter-to-ridge pathways on separate roof planes, one on the street or driveway side. The ridge setback is 18 inches, or 36 inches when panels cover more than 33% of the plan-view roof area.8
Usually not. Renewable Class I facilities of 25 kW or less are cap exempt, so most home systems can net meter even when a utility's cap is full.15
For Program Year 2026, systems of 25 kW AC or less get a flat $0.03 per kWh generated, or $0.06 for low-income customers. This is on top of net metering credits.14
Metro pages for Massachusetts: Boston.
Roof, attic and service panel in one visit
Explore →Roof, structure and switchgear
Explore →Terrain, build and operations
Explore →Roof and electrical, one visit
Explore →Stamped sets, six days from survey
Explore →SA, TOF and TSRF per plane
Explore →Every local fact on this page links to where it came from. Codes, programs and tariffs change: confirm the current requirement with the AHJ and the utility before you design.
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