Boston / Waltham
Waltham has 64,902 residents (give or take 43) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=060XX00US2501772600, checked 2026-10-19), about 5,092 people per square mile.
Waltham is about 12 miles from the Census center point for Boston in a straight line and covers 12.745 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).
The quote form takes a ZIP code; for Waltham that is 02451, 02452, 02453 (Census 2020 ZCTA to county subdivision relationship file, ZIP areas at least 20% inside the town, https://www2.census.gov/geo/docs/maps-data/data/rel2020/zcta520/tab20_zcta520_cousub20_natl.txt, checked 2026-10-19).
Median household income in Waltham is $120,216 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=060XX00US2501772600, 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.
5,092 people per square mile puts Waltham in suburban density, where the outdoor unit usually sits in a side yard and the noise is not an issue for neighbors.
37% of Waltham homes are single-family detached, 23% are in two- to four-unit buildings and 31% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=060XX00US2501772600, checked 2026-10-19).
50% of Waltham homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=060XX00US2501772600, checked 2026-10-19), so beside the 37% detached houses there is a real share of jobs where the landlord, not the resident, signs the quote.
Waltham has 9 points fewer detached houses than Middlesex County overall (46%) (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US25017, checked 2026-10-19).
50% of Waltham homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=060XX00US2501772600, 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.
Of the 25,498 occupied homes in Waltham, 53% heat with natural gas, 19% with heating oil, 24% with electricity and 3% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=060XX00US2501772600, checked 2026-10-19).
Gas leads in Waltham at 53%, but 22% of homes still burn delivered oil or propane, and those 5,610 or so homes are where a heat pump pays back fastest.
Waltham has about the Middlesex County oil share of 18% and 6 points more electric heat than the county's 18% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US25017, checked 2026-10-19).
Eversource Energy lists Waltham 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 Waltham 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).
Waltham has 26,728 housing units, 28% built before 1940 and 69% before 1980, with 15% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=060XX00US2501772600, checked 2026-10-19).
Waltham has 4 points fewer pre-1940 homes than Middlesex County as a whole (32%) (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US25017, checked 2026-10-19).
The median Waltham home was built in 1961 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=060XX00US2501772600, checked 2026-10-19) and the median home has 5 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=060XX00US2501772600, checked 2026-10-19).
Only 15% of Waltham homes are new enough to pass the whole-home rebate's weatherization check on age, and 28% date from before 1940, so most of the other 85% show it with a home energy assessment before the heat pump goes in.
Heating design temperature: 1F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Middlesex 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 Middlesex County cold-day number a Waltham 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 53% of Waltham on gas and 24% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; the median Waltham home has 5 rooms and was built around 1961, and the count of heads and the tonnage follow the rooms and the insulation, not the square footage.
The form on this page is the follow-up for Waltham. The public number is the number the contractor quotes from.
No local contractor is named on this door for Waltham yet. A request from this page goes to the first licensed shop that takes the door.