San Francisco / Castro Valley
Castro Valley has 65,001 residents (give or take 2,001) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US0611964, checked 2026-10-19), about 3,858 people per square mile.
Castro Valley is about 53 miles from the Census center point for San Francisco in a straight line and covers 16.848 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 Castro Valley that is 94546, 94578 (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).
3,858 people per square mile puts Castro Valley in suburban density, where the outdoor unit usually sits in a side yard and the noise is not an issue for neighbors.
Of the 22,021 occupied homes in Castro Valley, 71% heat with natural gas, 0% with heating oil, 24% with electricity and 3% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US0611964, checked 2026-10-19).
Gas heats 71% of Castro Valley against electricity at 24%, and a cold-climate heat pump sized for this market replaces the gas system outright, so the usual quote is a whole-home install.
Castro Valley has about the Alameda County oil share of 0% and 6 points less electric heat than the county's 30% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US06001, checked 2026-10-19).
Castro Valley has 22,957 housing units, 3% built before 1940 and 68% before 1980, with 7% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US0611964, checked 2026-10-19).
Castro Valley has 17 points fewer pre-1940 homes than Alameda County as a whole (20%) and 8 points fewer homes built after 2000 than the county's 15% (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US06001, checked 2026-10-19).
The median Castro Valley home was built in 1966 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US0611964, checked 2026-10-19) and the median home has 5.6 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US0611964, checked 2026-10-19).
73% of Castro Valley homes are single-family detached, 5% are in two- to four-unit buildings and 12% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US0611964, checked 2026-10-19).
With 73% detached houses and 5% in small multi-family buildings, a Castro Valley quote is usually one or two outdoor units with ducted or ductless heads sized room by room. With 27% of Castro Valley homes rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US0611964, checked 2026-10-19), the landlord signs the quote in many of them.
Castro Valley has 22 points more detached houses than Alameda County overall (51%) and 17 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=050XX00US06001, checked 2026-10-19).
68% of Castro Valley homes were built before 1980 and only 7% in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US0611964, 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 Castro 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 Castro Valley address before counting it. With 24% of Castro Valley homes already on electric heat and 74% 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 Castro Valley is $142,779 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US0611964, 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), Alameda 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 Alameda County cold-day number a Castro 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 71% of Castro Valley on gas and 24% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; the median Castro Valley home has 5.6 rooms and was built around 1966, 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 Castro Valley. The public number is the number the contractor quotes from.
No local contractor is named on this door for Castro Valley yet. A request from this page goes to the first licensed shop that takes the door.