St. Louis / Washington
Washington has 15,130 residents (give or take 26) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US2977416, checked 2026-10-19), about 1,510 people per square mile.
Washington is about 42 miles from the Census center point for St. Louis in a straight line and covers 10.022 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).
Of the 6,702 occupied homes in Washington, 29% heat with natural gas, 2% with heating oil, 66% with electricity and 2% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US2977416, checked 2026-10-19).
Electricity already heats 66% of Washington homes, ahead of gas at 29%, and a home on electric baseboard sees the biggest bill change from a heat pump because it replaces resistance heat one for one.
Washington has about the Franklin County oil share of 1% and 2 points less electric heat than the county's 68% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US29071, checked 2026-10-19).
Washington has 6,889 housing units, 17% built before 1940 and 53% before 1980, with 26% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US2977416, checked 2026-10-19).
Washington has 7 points more pre-1940 homes than Franklin County as a whole (10%) (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US29071, checked 2026-10-19). An older stock means more insulation upgrades before the heat pump goes in.
The median Washington home was built in 1978 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US2977416, checked 2026-10-19) and the median home has 5.5 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US2977416, checked 2026-10-19).
73% of Washington homes are single-family detached, 9% 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=160XX00US2977416, checked 2026-10-19).
With 73% detached houses and 9% in small multi-family buildings, a Washington quote is usually one or two outdoor units with ducted or ductless heads sized room by room. With 26% of Washington homes rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US2977416, checked 2026-10-19), the landlord signs the quote in many of them.
No electric utility is on file for Washington 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 Washington is $79,173 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US2977416, 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: 2F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Franklin County row, 99% heating, PDF pages 68 to 73 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 2F figure is the Franklin County cold-day number a Washington heat pump is sized against, so ask the installer to show the system's heating output at 2F, not at the milder rating-label temperature.
Ask for the heat-loss calculation room by room; the median Washington home has 5.5 rooms and was built around 1978, 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 Washington. The public number is the number the contractor quotes from.
No local contractor is named on this door for Washington yet. A request from this page goes to the first licensed shop that takes the door.