Boston / Charlestown
The figures on this page cover ZIP code 02129, the code a state office list files under Charlestown (BOSTON OFFICES BY ZIP CODE (Massachusetts Department of Children and Families), https://www.mass.gov/doc/boston-dcf-coverage-by-zip-code/download, checked 2026-10-19).
Charlestown has 20,032 residents (give or take 1,079) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=860Z200US02129, checked 2026-10-19), about 14,839 people per square mile.
Charlestown is about 4 miles from the Census center point for Boston in a straight line and covers 1.35 square miles of land (Census 2024 Gazetteer internal points and land area, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/, checked 2026-10-19).
At 14,839 people per square mile, Charlestown is dense enough that noise setback rules and outdoor-unit placement on a small lot are the first questions the installer works through.
Of the 9,606 occupied homes in Charlestown, 56% heat with natural gas, 3% with heating oil, 37% with electricity and 2% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=860Z200US02129, checked 2026-10-19).
Gas heats 56% of Charlestown against electricity at 37%, so most quotes here are a partial-home system that carries the shoulder seasons and the summer while the gas furnace handles the coldest nights, or a whole-home system when the house is ready for it.
Charlestown has 4 points less oil heat than Suffolk County as a whole, where 7% of homes burn oil, and 6 points more electric heat than the county's 31% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US25025, checked 2026-10-19).
6% of Charlestown homes are single-family detached, 33% are in two- to four-unit buildings and 45% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=860Z200US02129, checked 2026-10-19).
With 45% of Charlestown homes in buildings of five or more units and 6% detached, the condo association usually decides where outdoor units can go, so that approval comes before the quote. With 49% of Charlestown homes rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=860Z200US02129, checked 2026-10-19), the landlord signs the quote in many of them.
Charlestown has 7 points fewer detached houses than Suffolk County overall (13%) (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US25025, checked 2026-10-19).
Charlestown has 10,107 housing units, 50% built before 1940 and 73% before 1980, with 16% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=860Z200US02129, checked 2026-10-19).
Charlestown has 4 points more pre-1940 homes than Suffolk County as a whole (46%) (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US25025, checked 2026-10-19). An older stock means more insulation upgrades before the heat pump goes in.
The median Charlestown home was built in 1938 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=860Z200US02129, checked 2026-10-19) and the median home has 4 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=860Z200US02129, checked 2026-10-19).
49% of Charlestown homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=860Z200US02129, checked 2026-10-19), so the market splits between resident-led jobs where the occupant picks the system and landlord-led jobs where they do not, and the rebate paperwork differs.
Eversource Energy lists Charlestown among the Massachusetts communities it serves for electricity (Eversource Energy communities we serve, https://www.eversource.com/residential/services/communities-we-serve, checked 2026-10-19).
For a Charlestown address billed by Eversource Energy, the Mass Save whole-home heat pump rebate is $2,650 per ton up to $8,500, and the partial-home rebate is $1,125 per ton up to $8,500; for projects installed on or after January 1, 2027, the whole-home figure drops to $2,350 per ton capped at $7,500 (Mass Save air-source heat pump rebates, https://www.masssave.com/residential/rebates-offers-services/heating-and-cooling/heat-pumps/air-source-heat-pumps, checked 2026-10-19).
With 50% of homes built before 1940 and only 16% new enough to pass on age, the first question for a Charlestown house is insulation: the whole-home rebate wants proof the house is weatherized, and a no-cost home energy assessment is the usual way an older home shows it.
Median household income in Charlestown is $157,247 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=860Z200US02129, checked 2026-10-19); Mass Save's enhanced heat pump incentives are income-based and decided household by household, so the town median only hints at how many neighbors qualify.
Heating design temperature: 1F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Suffolk County row, 99% heating, PDF page 56 of 141 (Revised 11/11/2020), https://www.energystar.gov/sites/default/files/Design%20Temperature%20Limit%20Reference%20Guide%20(2019%20Ed)%20-%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev11.pdf, fetched 2026-10-19, 99%.
That 1F figure is the Suffolk County cold-day number a Charlestown heat pump is sized against, so ask the installer to show the system's heating output at 1F, not at the milder rating-label temperature.
Ask whether the quote is whole-home or partial-home, because with 56% of Charlestown on gas and 37% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; a Charlestown house from before 1940 (50% of the 10,107 units) rarely matches a square-footage rule of thumb.
The form on this page is the follow-up for Charlestown. The public number is the number the contractor quotes from.
No local contractor is named on this door for Charlestown yet. A request from this page goes to the first licensed shop that takes the door.