Arlington / Chantilly
Chantilly has 24,036 residents (give or take 1,426) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US5114744, checked 2026-10-19), about 2,003 people per square mile.
Chantilly is about 18 miles from the Census center point for Arlington in a straight line and covers 12.002 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 Chantilly that is 20151 (Census 2020 ZCTA to county subdivision and ZCTA to place relationship files, ZIP areas at least 20% inside the town, https://www2.census.gov/geo/docs/maps-data/data/rel2020/zcta520/tab20_zcta520_cousub20_natl.txt and https://www2.census.gov/geo/docs/maps-data/data/rel2020/zcta520/tab20_zcta520_place20_natl.txt, checked 2026-10-19).
Of the 7,552 occupied homes in Chantilly, 49% heat with natural gas, 0% with heating oil, 48% with electricity and 2% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US5114744, checked 2026-10-19).
Gas heats 49% of Chantilly against electricity at 48%, 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.
Chantilly has about the Fairfax County oil share of 1% and 6 points more electric heat than the county's 42% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US51059, checked 2026-10-19).
Chantilly has 7,598 housing units, 1% built before 1940 and 18% before 1980, with 23% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US5114744, checked 2026-10-19).
Chantilly has 3 points more homes built after 2000 than the county's 20% (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US51059, checked 2026-10-19).
The median Chantilly home was built in 1987 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US5114744, checked 2026-10-19) and the median home has 7.2 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US5114744, checked 2026-10-19).
61% of Chantilly homes are single-family detached, 2% are in two- to four-unit buildings and 9% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US5114744, checked 2026-10-19).
19% of Chantilly homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US5114744, checked 2026-10-19), so beside the 61% detached houses there is a real share of jobs where the landlord, not the resident, signs the quote.
Chantilly has 15 points more detached houses than Fairfax County overall (46%) and 20 points fewer five-plus-unit buildings than the county's 29% (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US51059, checked 2026-10-19).
No electric utility is on file for Chantilly on this door yet, so this page does not name one; the name on the bill decides which rebate path applies.
Median household income in Chantilly is $157,124 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US5114744, checked 2026-10-19); many state and utility heat pump rebate programs set higher incentive tiers for income-qualifying households, so the household income on the application, not the town median, decides which level applies.
Heating design temperature: 14F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Fairfax County row, 99% heating, PDF pages 127 to 133 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 14F figure is the Fairfax County cold-day number a Chantilly heat pump is sized against, so ask the installer to show the system's heating output at 14F, not at the milder rating-label temperature.
Ask whether the quote is whole-home or partial-home, because with 49% of Chantilly on gas and 48% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; the median Chantilly home has 7.2 rooms and was built around 1987, 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 Chantilly. The public number is the number the contractor quotes from.
No local contractor is named on this door for Chantilly yet. A request from this page goes to the first licensed shop that takes the door.