Wilmington / New Castle
New Castle has 5,579 residents (give or take 23) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US1050800, checked 2026-10-19), about 1,604 people per square mile.
New Castle is about 5 miles from the Census center point for Wilmington in a straight line and covers 3.478 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).
Median household income in New Castle is $89,205 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US1050800, 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.
37% of New Castle homes are single-family detached, 7% are in two- to four-unit buildings and 26% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US1050800, checked 2026-10-19).
37% of New Castle homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US1050800, 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.
New Castle has 16 points fewer detached houses than New Castle County overall (53%) (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US10003, checked 2026-10-19).
Of the 2,774 occupied homes in New Castle, 76% heat with natural gas, 4% with heating oil, 18% with electricity and 0% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US1050800, checked 2026-10-19).
Gas heats 76% of New Castle against electricity at 18%, 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.
New Castle has 5 points less oil heat than New Castle County as a whole, where 9% of homes burn oil, and 14 points less electric heat than the county's 32% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US10003, checked 2026-10-19).
No electric utility is on file for New Castle on this door yet, so this page does not name one; the name on the bill decides which rebate path applies.
New Castle has 2,877 housing units, 39% built before 1940 and 67% before 1980, with 20% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US1050800, checked 2026-10-19).
New Castle has 28 points more pre-1940 homes than New Castle County as a whole (11%) (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US10003, checked 2026-10-19). An older stock means more insulation upgrades before the heat pump goes in.
The median New Castle home was built in 1959 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US1050800, checked 2026-10-19) and the median home has 5.8 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US1050800, checked 2026-10-19).
39% of New Castle homes were built before 1940 and 67% before 1980 (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US1050800, checked 2026-10-19), so insulation is the first sizing question: an older home leaks more heat per square foot, and the installer runs a room-by-room heat-loss calculation to size the system for what the walls and windows actually hold in, not just the floor plan.
Heating design temperature: 11F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), New Castle County row, 99% heating, PDF page 17 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 11F figure is the New Castle County cold-day number a New Castle heat pump is sized against, so ask the installer to show the system's heating output at 11F, not at the milder rating-label temperature.
Ask whether the quote is whole-home or partial-home, because with 76% of New Castle on gas and 18% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; a New Castle house from before 1940 (39% of the 2,877 units) rarely matches a square-footage rule of thumb.
The form on this page is the follow-up for New Castle. The public number is the number the contractor quotes from.
No local contractor is named on this door for New Castle yet. A request from this page goes to the first licensed shop that takes the door.