Licensing & Regulation
- CSL (Construction Supervisor License)
- Examination-based MA license required to pull building permits and supervise structural work, issued by the Board of Building Regulations and Standards (BBRS) under MGL c.143. See our CSL reference.
- HIC (Home Improvement Contractor)
- MA registration required for any residential improvement work over $1,000, issued by the Office of Consumer Affairs and Business Regulation (OCABR) under MGL c.142A. Unlocks the $10,000 Guaranty Fund. See our HIC reference.
- Master Plumber License
- MA license required for plumbing work over $500 OR involving gas. Issued by the MA Board of State Examiners of Plumbers and Gas Fitters under 248 CMR.
- Master Electrician License
- MA license required for electrical work over $500. Issued by the MA Board of State Examiners of Electricians under 527 CMR.
- Gas Fitter License
- MA license specific to gas piping work — covered by 248 CMR 6. Distinct from Master Plumber though often held by the same person.
- Massachusetts Home Improvement Contractor Guaranty Fund
- State-administered fund providing up to $10,000 recovery to homeowners harmed by registered HIC contractors. Funded by HIC registration fees.
- OCABR
- Massachusetts Office of Consumer Affairs and Business Regulation — the state agency administering HIC registration and home improvement consumer protection.
- BBRS
- Board of Building Regulations and Standards — the state agency administering 780 CMR State Building Code and the CSL license.
Building Codes
- 780 CMR
- Massachusetts State Building Code — statewide minimum for all construction, based on IRC 2021 + IBC 2021. See our 780 CMR reference.
- 248 CMR
- Massachusetts Uniform State Plumbing Code — governs all plumbing and gas fitting. See our 248 CMR reference.
- 527 CMR
- Massachusetts Electrical Code — adopts NEC 2020 with MA amendments. See our 527 CMR reference.
- Massachusetts Stretch Energy Code
- Voluntary stricter energy code adopted by 290+ MA municipalities. ~12-20% energy savings vs base 780 CMR. See our Stretch Code reference.
- Specialized Stretch Code
- Net Zero variant of the Massachusetts Stretch Code, adopted by 30+ municipalities, requiring Net Zero-ready construction by 2030.
- IRC 2021
- International Residential Code 2021 edition — the base for 780 CMR residential provisions.
- IBC 2021
- International Building Code 2021 edition — the base for 780 CMR commercial provisions.
- NEC 2020
- National Electrical Code 2020 edition — base for 527 CMR. Published by NFPA.
- NEC Article 220
- National Electrical Code section governing electrical service load calculation. Required before circuit additions affecting service capacity.
Energy Programs
- Mass Save
- Massachusetts statewide energy efficiency program funded by utility ratepayer surcharges. $1.5B+ annual budget. Operates rebates for heat pumps, weatherization, water heaters, and other efficiency measures. See our Mass Save reference.
- HPC (Heat Pump Coach)
- Mass Save contractor authorization required to file heat pump rebates. Separate from general Mass Save authorization. Identified by numeric HPC ID in the Mass Save contractor directory.
- HEA (Home Energy Assessment)
- Free 90-minute Mass Save audit identifying weatherization opportunities and air leakage. Prerequisite for all Mass Save weatherization rebates.
- Income Eligible Enhanced
- Mass Save's highest rebate tier (households below 60% Area Median Income). Up to 100% coverage of qualifying weatherization. $16K whole-home heat pump rebate.
- HEAT Loan
- Mass Save's 0% interest financing facility — up to $50,000 over 7 years for qualifying energy upgrades. See our HEAT Loan reference.
- IRC §25C
- Federal tax credit for energy efficient home improvements — up to $2,000 for heat pumps + $1,200 for envelope improvements. See our IRC §25C reference.
- MOR-EV
- Massachusetts Offers Rebates for Electric Vehicles — state EV purchase rebate up to $3,500 ($5,000 for low-income buyers). Administered by MassCEC. See our MOR-EV reference.
- MassCEC
- Massachusetts Clean Energy Center — state agency administering MOR-EV and various clean energy programs.
- Massachusetts DOER
- Massachusetts Department of Energy Resources — sets state energy policy, manages Stretch Code adoption.
HVAC Terminology
- HSPF2
- Heating Seasonal Performance Factor 2 — efficiency metric for heat pump heating. ≥7.5 required for Mass Save rebate eligibility in MA Climate Zones 5-7.
- SEER2
- Seasonal Energy Efficiency Ratio 2 — efficiency metric for cooling. ≥15.2 required for Mass Save rebate eligibility on heat pumps.
- AHRI Reference Number
- Air-Conditioning, Heating, and Refrigeration Institute certification number identifying a matched indoor coil + outdoor condenser pair tested together. Required in writing for Mass Save rebate filing.
- Manual J
- ACCA Manual J 8th Edition — standardized residential heating/cooling load calculation method. Required by Mass Save for all authorized HPC installs.
- Manual D
- ACCA Manual D — ductwork sizing methodology. Required when retrofitting heat pump to existing ductwork.
- NEEP CCASHP
- Northeast Energy Efficiency Partnerships Cold-Climate Air-Source Heat Pump Specification — verified heat pump models maintaining capacity at 5°F. Reference list for cold-climate selection.
- R-32
- HFC refrigerant (difluoromethane) — lower-GWP alternative to R-410A. Used by Bosch, Mr. Cool, LG, Daikin heat pumps. 2026 Mass Save rebate-eligible.
- R-454B
- HFO/HFC blend refrigerant — lower-GWP alternative to R-410A. Used by Mitsubishi, Fujitsu, Carrier, Trane, Lennox, Rheem heat pumps. 2026 Mass Save rebate-eligible.
- R-410A
- Legacy HFC refrigerant phased out under the federal AIM Act for new manufacturing. NOT eligible for 2026 Mass Save rebates.
- R-22
- Legacy HCFC refrigerant phased out 2010-2020. Recycled R-22 sells for $200-$400/lb. Leak repair on R-22 systems is often uneconomic vs replacement.
- AIM Act
- American Innovation and Manufacturing Act — federal HFC phase-down requiring transition to lower-GWP refrigerants.
- ATS (Automatic Transfer Switch)
- Standby generator component that automatically transfers home electrical load from utility to generator when utility power fails.
Roofing & Siding
- HardieZone System
- James Hardie's North American climate-zone classification for fiber cement siding spec. All of Massachusetts falls in HardieZone 5.
- ColorPlus Technology
- James Hardie's factory-applied finish system with 15-year fade warranty.
- ASTM D7158
- Standard test method for asphalt shingle wind resistance. Class F = 110 mph, Class G = 120 mph, Class H = 150 mph design wind speed.
- AR (Algae-Resistant) Shingles
- Asphalt shingles with copper-infused granules preventing Gloeocapsa magma algae growth — the cause of black streaking visible on aging roofs.
- Ice and Water Shield
- Self-adhering rubberized membrane installed under shingles. Required at eaves under 780 CMR; full-deck coverage recommended for coastal MA.
- Rainscreen
- 1/4-inch furring strips creating drainage plane behind exterior cladding. Critical for fiber cement (Hardie) longevity in coastal MA installs.
Plumbing Terminology
- TPR (Temperature/Pressure Relief) Valve
- Water heater safety valve releasing water if heater overheats or overpressurizes. 248 CMR requires specific discharge pipe configuration.
- CIPP (Cured-In-Place Pipe)
- Trenchless sewer line repair — resin-saturated liner inverted into existing pipe, then cured to form new structural pipe. ASTM F1216 standard.
- Hydro-Jetting
- Sewer line cleaning using high-pressure water (2,500-4,000 PSI) to clear roots, grease, and debris.
- Dielectric Union
- Plumbing fitting separating dissimilar metals (copper meeting galvanized) to prevent galvanic corrosion. Required by 248 CMR at water heater connections.
- Thermal Expansion Tank
- Pressure vessel accommodating water expansion when heated. Required by 248 CMR on systems with backflow preventer.
- Vacuum Breaker
- Backflow prevention device required on outdoor hose bibs per 248 CMR 10.14.
Electrical Terminology
- 100A / 200A Service
- Electrical service capacity in amperes. 100A typical for pre-2005 MA homes; 200A typical for new construction. Whole-home electrification often requires 200A upgrade.
- GFCI
- Ground-Fault Circuit Interrupter — required by NEC 210.8 in bathrooms, kitchens, garages, exteriors.
- AFCI
- Arc-Fault Circuit Interrupter — required by NEC 210.12 in bedrooms and living spaces.
- Level 2 EV Charger
- 240V EV charging equipment delivering 6-12 kW (25-50 miles of range per hour). Distinct from Level 1 (120V) and Level 3 (DC Fast).
- SAE J1772
- North American Level 1 + Level 2 EV charging connector standard. Used by all non-Tesla EVs through 2024.
- SAE J3400 (NACS)
- North American Charging Standard — the standardized Tesla connector. Adopted as universal by Ford, GM, Hyundai, Kia for 2025+ EVs.
Construction Terminology
- ADU (Accessory Dwelling Unit)
- Secondary dwelling on a single-family lot — detached cottage, garage conversion, basement unit, etc. Permitted by-right in 177 MA municipalities under MBTA Communities Act.
- MGL c.40A §3A
- Massachusetts General Law Chapter 40A Section 3A — the MBTA Communities Act requiring multi-family / ADU zoning in MBTA-served municipalities.
- MBTA Communities Act
- Common name for MGL c.40A §3A. Requires 177 MA municipalities to allow multi-family/ADU housing by-right near MBTA service.
- ASHRAE 99% Design Temperature
- Outdoor temperature design value used in HVAC sizing. Western MA: -3°F to -5°F. Eastern MA: 5°F to 9°F.