State facts
Massachusetts: homes, climate zones and who licenses the work
Massachusetts has 3.0 million housing units. 67.4% were built before 1980, and the median year built is 1964. 62.5% of occupied homes are lived in by their owners.
How old the homes are
Massachusetts housing units, by year built
Layers drawn to scale
Age changes what applies to a house. In general, anyone paid to do work that disturbs painted surfaces in a home built before 1978 must be certified in lead-safe work practices under the EPA's Renovation, Repair and Painting Rule, which Massachusetts Department of Labor Standards administers in Massachusetts.
How homes are heated
How homes in Massachusetts are heated
Main heating fuel, share of 2.8 million occupied homes
- Utility gas 51.6%
- Fuel oil or kerosene 22.4%
- Electricity 18.6%
- Propane or other tank gas 4.5%
- Wood 1.1%
- Other fuel 0.8%
- No fuel used 0.7%
- Solar energy 0.2%
- Coal or coke <0.1%
Climate and building zones
The 2021 International Energy Conservation Code assigns every county a climate zone from 1 to 8 and a moisture regime: A for moist, B for dry, C for marine. Zones 7 and 8 have no letter. Here is how Massachusetts's residents divide among them, by the county they live in.
| IECC 2021 zone | Share of residents | Counties |
|---|---|---|
| 5A | 100% | 14 |
ENERGY STAR rates windows, doors and skylights for four climate zones of its own. All of Massachusetts falls in the Northern zone.
By NOAA's 1991–2020 climate normals, counties here average 131 days a year with a low of 32°F or colder, weighted by where people live. The range runs from 86 days in the mildest county to 166 in the coldest.
- SEER2 Requirements by State: What a New AC Must Meet
- What Size AC Do I Need? How a Load Calculation Answers It
- Do Heat Pumps Work in Cold Weather? What to Check Before Buying
- No Heat in Winter: How to Stay Safe Until the Furnace Is Fixed
- Ice Dams: Why They Leak Into Ceilings and How to Stop Them
- Crawl Space Moisture: Vented vs. Sealed Crawl Spaces
- Condensation on the Inside of Windows: Causes and Fixes
Flood risk and flood insurance
2% of residential structures in Massachusetts carry a National Flood Insurance Program policy: 36,939 policies, in FEMA's count as of August 3, 2026.
In FEMA's National Risk Index, 7 of 14 counties rate high or very high for riverine flooding; 5 of 14 counties rate high or very high for coastal flooding; 6 of 14 counties rate high or very high for hurricanes.
Fire ants and termites
No county in Massachusetts is inside the federal imported fire ant quarantine.
Who licenses the work in Massachusetts
Before anyone starts work, check the license with the agency below. Where the state does not license a trade, cities and counties may; ask the one where the house is.
- Pest control The department issues individual pesticide certifications and licenses, such as certified commercial applicator and licensed applicator, in categories and subcategories it sets. Agency: Massachusetts Department of Agricultural Resources, Pesticide Program. Look up a license. Who to call about pest control.
- Heating and cooling Massachusetts has no single HVAC contractor license; the state licenses refrigeration technicians for refrigerant systems of 10 tons or more and sheet metal workers for commercial duct systems. Agency: Division of Occupational Licensure (Office of Public Safety and Inspections; Board of Examiners of Sheet Metal Workers). Look up a license. Who to call about heating and cooling.
- Window replacement and other home improvement Contractors and subcontractors who do residential contracting work on existing owner-occupied homes of one to four units must register as Home Improvement Contractors; state guidance lists window installation or replacement as needing a Window/Siding Construction Supervisor License plus HIC registration. Agency: Office of Consumer Affairs and Business Regulation, Home Improvement Contractor Program (HIC); Office of Public Safety and Inspections (Construction Supervisor License). Look up a license. Who to call about window replacement.
- Mold remediation No statewide license. Massachusetts does not require a license to conduct mold remediation. Who to call about water damage and mold.
Checked 2026-09-29. Licensing rules change; the agency's own page is the authority.
Sources
- U.S. Census Bureau American Community Survey 2020–2024 5-year estimates, tables B25034, B25035, B25040 and B25003 data.census.gov
- Pacific Northwest National Laboratory Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates basc.pnnl.gov
- U.S. Department of Energy Prototype Building Models (climate zones 1–8 and moisture regimes A, B, C) energycodes.gov
- ENERGY STAR Climate zones by county for windows, doors and skylights energystar.gov
- NOAA National Centers for Environmental Information U.S. Climate Normals 1991–2020, annual and seasonal ncei.noaa.gov
- Federal Emergency Management Agency OpenFEMA NFIP Residential Penetration Rates (as of 2026-08-03) fema.gov
- Federal Emergency Management Agency National Risk Index, county ratings fema.gov
- USDA Animal and Plant Health Inspection Service Imported fire ant quarantine map aphis.usda.gov
- Electronic Code of Federal Regulations 7 CFR part 301, subpart P, Imported Fire Ant ecfr.gov
- Massachusetts Department of Agricultural Resources, Pesticide Program mass.gov mass.gov
- Massachusetts Department of Agricultural Resources, Pesticide Program malegislature.gov malegislature.gov
- Massachusetts Department of Agricultural Resources, Pesticide Program malegislature.gov malegislature.gov
- Massachusetts Department of Agricultural Resources, Pesticide Program npic.orst.edu npic.orst.edu
- Massachusetts Department of Agricultural Resources, Pesticide Program mass.gov mass.gov
- Division of Occupational Licensure (Office of Public Safety and Inspections; Board of Examiners of Sheet Metal Workers) malegislature.gov malegislature.gov
- Division of Occupational Licensure (Office of Public Safety and Inspections; Board of Examiners of Sheet Metal Workers) malegislature.gov malegislature.gov
- Division of Occupational Licensure (Office of Public Safety and Inspections; Board of Examiners of Sheet Metal Workers) malegislature.gov malegislature.gov
- Division of Occupational Licensure (Office of Public Safety and Inspections; Board of Examiners of Sheet Metal Workers) malegislature.gov malegislature.gov
- Division of Occupational Licensure (Office of Public Safety and Inspections; Board of Examiners of Sheet Metal Workers) malegislature.gov malegislature.gov
- Division of Occupational Licensure (Office of Public Safety and Inspections; Board of Examiners of Sheet Metal Workers) mass.gov mass.gov
- Office of Consumer Affairs and Business Regulation, Home Improvement Contractor Program (HIC); Office of Public Safety and Inspections (Construction Supervisor License) mass.gov mass.gov
- Office of Consumer Affairs and Business Regulation, Home Improvement Contractor Program (HIC); Office of Public Safety and Inspections (Construction Supervisor License) malegislature.gov malegislature.gov
- Office of Consumer Affairs and Business Regulation, Home Improvement Contractor Program (HIC); Office of Public Safety and Inspections (Construction Supervisor License) malegislature.gov malegislature.gov
- Office of Consumer Affairs and Business Regulation, Home Improvement Contractor Program (HIC); Office of Public Safety and Inspections (Construction Supervisor License) contractorhub.mass.gov contractorhub.mass.gov
- Office of Consumer Affairs and Business Regulation, Home Improvement Contractor Program (HIC); Office of Public Safety and Inspections (Construction Supervisor License) mass.gov mass.gov
- mass.gov mass.gov mass.gov
- Massachusetts Department of Labor Standards epa.gov epa.gov
- Massachusetts Department of Labor Standards mass.gov mass.gov