San Francisco / Mill Valley
Mill Valley has 14,012 residents (give or take 26) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US0647710, checked 2026-10-19), about 2,930 people per square mile.
Mill Valley is about 30 miles from the Census center point for San Francisco in a straight line and covers 4.782 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 5,688 occupied homes in Mill Valley, 73% heat with natural gas, 0% with heating oil, 23% with electricity and 0% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US0647710, checked 2026-10-19).
Gas heats 73% of Mill Valley against electricity at 23%, and a cold-climate heat pump sized for this market replaces the gas system outright, so the usual quote is a whole-home install.
Mill Valley has about the Marin County oil share of 0% and 3 points less electric heat than the county's 26% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US06041, checked 2026-10-19).
Mill Valley has 6,418 housing units, 28% built before 1940 and 80% before 1980, with 8% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US0647710, checked 2026-10-19).
Mill Valley has 15 points more pre-1940 homes than Marin County as a whole (13%) (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US06041, checked 2026-10-19). An older stock means more insulation upgrades before the heat pump goes in.
The median Mill Valley home was built in 1958 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US0647710, 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=160XX00US0647710, checked 2026-10-19).
70% of Mill Valley homes are single-family detached, 8% are in two- to four-unit buildings and 13% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US0647710, checked 2026-10-19).
With 70% detached houses and 8% in small multi-family buildings, a Mill Valley quote is usually one or two outdoor units with ducted or ductless heads sized room by room. With 34% of Mill Valley homes rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US0647710, checked 2026-10-19), the landlord signs the quote in many of them.
Mill Valley has 7 points more detached houses than Marin County overall (63%) (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US06041, checked 2026-10-19).
80% of Mill Valley homes were built before 1980 and only 8% in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US0647710, 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 Mill Valley on this door yet, so this page does not name one; the name on the bill decides which rebate path applies.
LADWP Consumer Rebate Program heat pump HVAC, run by LADWP, is a live program for California addresses and publishes its terms without one headline figure (registry row 24 verified 2026-10-14, https://www.ladwp.com/residential-services/assistance-programs/consumer-rebate-program, checked 2026-10-16); confirm eligibility for the Mill Valley address before counting it. With 23% of Mill Valley homes already on electric heat and 73% 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 Mill Valley is $206,212 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US0647710, 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: 27F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Marin County row, 99% heating, PDF pages 11 to 13 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 27F figure is the Marin County cold-day number a Mill Valley heat pump is sized against, so ask the installer to show the system's heating output at 27F, not at the milder rating-label temperature.
Ask whether the quote is whole-home or partial-home, because with 73% of Mill Valley on gas and 23% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; the median Mill Valley home has 5.5 rooms and was built around 1958, 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 Mill Valley. The public number is the number the contractor quotes from.
No local contractor is named on this door for Mill Valley yet. A request from this page goes to the first licensed shop that takes the door.