Charleston / James Island
James Island is about 7 miles from the Census center point for Charleston in a straight line and covers 4.84 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).
James Island has 12,198 residents (give or take 26) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US4536430, checked 2026-10-19), about 2,520 people per square mile.
Of the 4,666 occupied homes in James Island, 35% heat with natural gas, 0% with heating oil, 61% with electricity and 1% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US4536430, checked 2026-10-19).
James Island has about the Charleston County oil share of 0% and 15 points less electric heat than the county's 76% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US45019, checked 2026-10-19).
Electricity already heats 61% of James Island homes, ahead of gas at 35%, and a home on electric baseboard sees the biggest bill change from a heat pump because it replaces resistance heat one for one.
The median James Island home was built in 1970 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US4536430, checked 2026-10-19) and the median home has 6.7 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US4536430, checked 2026-10-19).
James Island has 4,971 housing units, 0% built before 1940 and 68% before 1980, with 11% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US4536430, checked 2026-10-19).
James Island has 5 points fewer pre-1940 homes than Charleston County as a whole (5%) and 28 points fewer homes built after 2000 than the county's 39% (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US45019, checked 2026-10-19).
68% of James Island homes were built before 1980 and only 11% in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US4536430, 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.
92% of James Island homes are single-family detached, 2% are in two- to four-unit buildings and 1% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US4536430, checked 2026-10-19).
With 92% detached houses and 2% in small multi-family buildings, a James Island quote is usually one or two outdoor units with ducted or ductless heads sized room by room. With 12% of James Island homes rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US4536430, checked 2026-10-19), the landlord signs the quote in many of them.
James Island has 34 points more detached houses than Charleston County overall (58%) and 22 points fewer five-plus-unit buildings than the county's 23% (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US45019, checked 2026-10-19).
Only 12% of James Island homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US4536430, checked 2026-10-19), so nearly every quote here is the resident talking to the installer directly, and the rebate goes to the person living in the house.
No electric utility is on file for James Island 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 James Island is $104,217 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US4536430, 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: 28F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Charleston County row, 99% heating, PDF pages 105 to 107 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 28F figure is the Charleston County cold-day number a James Island heat pump is sized against, so ask the installer to show the system's heating output at 28F, not at the milder rating-label temperature.
Ask for the heat-loss calculation room by room; the median James Island home has 6.7 rooms and was built around 1970, 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 James Island. The public number is the number the contractor quotes from.
No local contractor is named on this door for James Island yet. A request from this page goes to the first licensed shop that takes the door.