Madison / Fond du Lac
Fond du Lac has 44,494 residents (give or take 31) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US5526275, checked 2026-10-19), about 2,313 people per square mile.
Fond du Lac is about 69 miles from the Census center point for Madison in a straight line and covers 19.237 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 Fond du Lac that is 54935 (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 19,018 occupied homes in Fond du Lac, 75% heat with natural gas, 1% with heating oil, 19% with electricity and 3% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US5526275, checked 2026-10-19).
Gas heats 75% of Fond du Lac against electricity at 19%, 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.
Fond du Lac has about the Fond du Lac County oil share of 3% and 4 points more electric heat than the county's 15% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US55039, checked 2026-10-19).
Fond du Lac has 20,433 housing units, 28% built before 1940 and 66% before 1980, with 16% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US5526275, checked 2026-10-19).
Fond du Lac has 3 points more pre-1940 homes than Fond du Lac County as a whole (25%) and 3 points fewer homes built after 2000 than the county's 19% (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US55039, checked 2026-10-19). An older stock means more insulation upgrades before the heat pump goes in.
The median Fond du Lac home was built in 1967 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US5526275, checked 2026-10-19) and the median home has 5.4 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US5526275, checked 2026-10-19).
59% of Fond du Lac homes are single-family detached, 11% are in two- to four-unit buildings and 25% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US5526275, checked 2026-10-19).
42% of Fond du Lac homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US5526275, checked 2026-10-19), so beside the 59% detached houses there is a real share of jobs where the landlord, not the resident, signs the quote.
Fond du Lac has 11 points fewer detached houses than Fond du Lac County overall (70%) (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US55039, checked 2026-10-19).
42% of Fond du Lac homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US5526275, 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.
66% of Fond du Lac homes were built before 1980 and only 16% in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US5526275, checked 2026-10-19), so most of the stock predates modern insulation codes; the installer's heat-loss calculation, not a square-footage rule, decides the tonnage.
No electric utility is on file for Fond du Lac on this door yet, so this page does not name one; the name on the bill decides which rebate path applies.
Focus on Energy air source heat pump instant discount (ratepayer), run by Focus on Energy, is a live program for Wisconsin addresses and covers qualifying equipment at $900 per system (registry row 20 verified 2026-10-07, https://assets.focusonenergy.com/production/docs/trade-ally/TAS-Trade-Ally-Solutions-Rebates-Overview-20260101_CLEAN.pdf, checked 2026-10-16); confirm eligibility for the Fond du Lac address before counting it. With 19% of Fond du Lac homes already on electric heat and 79% on gas, oil or propane, the row that applies depends on the name on the electric bill and the fuel coming out.
Median household income in Fond du Lac is $62,260 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US5526275, 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), Fond du Lac County row, 99% heating, PDF pages 137 to 140 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 Fond du Lac County cold-day number a Fond du Lac 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 whether the quote is whole-home or partial-home, because with 75% of Fond du Lac on gas and 19% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; the median Fond du Lac home has 5.4 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 Fond du Lac. The public number is the number the contractor quotes from.
No local contractor is named on this door for Fond du Lac yet. A request from this page goes to the first licensed shop that takes the door.