Boston / Chelmsford
Chelmsford is about 25 miles from the Census center point for Boston in a straight line and covers 22.382 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).
Chelmsford has 36,446 residents (give or take 43) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=060XX00US2501713135, checked 2026-10-19), about 1,628 people per square mile.
The quote form takes a ZIP code; for Chelmsford that is 01824, 01863 (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).
Of the 13,450 occupied homes in Chelmsford, 77% heat with natural gas, 8% with heating oil, 10% with electricity and 2% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=060XX00US2501713135, checked 2026-10-19).
Chelmsford has 10 points less oil heat than Middlesex County as a whole, where 18% of homes burn oil, and 8 points less 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).
Gas heats 77% of Chelmsford against electricity at 10%, 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.
The median Chelmsford home was built in 1967 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=060XX00US2501713135, checked 2026-10-19) and the median home has 6.3 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=060XX00US2501713135, checked 2026-10-19).
Chelmsford has 13,942 housing units, 15% built before 1940 and 68% before 1980, with 13% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=060XX00US2501713135, checked 2026-10-19).
Chelmsford has 17 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).
Only 13% of Chelmsford homes are new enough to pass the whole-home rebate's weatherization check on age, and 15% date from before 1940, so most of the other 87% show it with a home energy assessment before the heat pump goes in.
67% of Chelmsford homes are single-family detached, 4% are in two- to four-unit buildings and 19% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=060XX00US2501713135, checked 2026-10-19).
18% of Chelmsford homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=060XX00US2501713135, checked 2026-10-19), so beside the 67% detached houses there is a real share of jobs where the landlord, not the resident, signs the quote.
Chelmsford has 21 points more 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).
No electric utility is on file for Chelmsford on this door yet, so this page does not name one; the name on the bill decides which rebate path applies.
If the Chelmsford electric bill comes from one of the Mass Save sponsors (Cape Light Compact, Eversource, National Grid, Unitil), the 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).
Median household income in Chelmsford is $140,629 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=060XX00US2501713135, 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), 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 Chelmsford 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 77% of Chelmsford on gas and 10% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; the median Chelmsford home has 6.3 rooms and was built around 1967, 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 Chelmsford. The public number is the number the contractor quotes from.
No local contractor is named on this door for Chelmsford yet. A request from this page goes to the first licensed shop that takes the door.