Which floor do you own? In Somerville, that question shapes a heat pump plan more than the brand or the size. Clement Boston Heat Pumps plans heat pump installation in Somerville, MA one floor at a time, because most homes here sit in two-families and three-deckers.
Somerville has the oldest housing of any city near Boston, with 59% of homes built before 1940. More than half are in two-to-four-unit buildings designed for radiators.
Planning floor by floor in Somerville
Each floor of a Somerville two-family or three-decker loses heat differently and has a different way in for ducts. We size and route each one separately.
| Floor | Where the air handler goes | What changes the plan |
|---|---|---|
| Top | Attic | Roof heat loss and summer heat gain |
| Middle | Closet or small-duct air handler | No attic or basement of its own |
| First | Basement | Shared space with the old boiler and meters |
Top floors and attics
The top floor loses the most heat through the roof. An attic air handler feeds it through short, sealed branches in the ceiling, and the same system cools the hottest rooms in the building.
The middle floor
The middle unit has neither attic nor basement. A closet air handler can feed most rooms through a dropped hallway ceiling; where that won’t reach, small-duct high-velocity tubing threads through walls and floors. Our ductwork page compares the two.
First floors and basements
The basement gives the first floor short runs and floor registers. It’s also where the old boiler, the meters and the other units’ pipes sit, so we lay out the new equipment to leave everything serviceable.
If the boiler still heats the floors above, it stays in service until the last unit converts, and the new return is kept well away from its combustion air.
What the city allows
Somerville’s rules are lighter than Cambridge’s on fuel and similar on paperwork. Three of them matter for a ducted job.
Gas backup is still an option
The state told Somerville in October 2024 that it was not selected for the fossil-fuel-free demonstration program. A renovation here can keep a gas furnace for the coldest hours beside a heat pump. See dual fuel heat pumps.
Since July 1, 2023, Somerville has followed the specialized stretch code, which steers new construction and major renovations toward all-electric or pre-wired designs. A like-for-like replacement is unaffected.
Sheet metal permits
Ducted work needs a sheet metal permit of its own, on top of the electrical permit. Of 871 Somerville permit applications that named a space-heating heat pump between November 2021 and October 2026, 356 were sheet metal permits, and ducted systems outnumbered ductless ones.
Historic districts and yards
In a local historic district, the Historic Preservation Commission reviews exterior changes visible from a public way. We photograph the outdoor spot from the street on the first visit. Zoning setbacks for equipment on tight side yards are confirmed per address.
Where heat pump work is happening
The city’s permit data shows where owners are already converting. Spring Hill led with 151 applications, followed by Union Square with 126, Davis Square and Winter Hill with 105 each.
Spring Hill and Winter Hill
These hills hold many of the city’s oldest two-families and three-deckers, often on steam or hot-water radiators. The boiler conversion page covers the switch, and our old houses guide shows where ducts hide in plaster walls.
Condos around the squares
Where a two-family near Davis, Porter or Teele Square has been split into condos, each owner plans their own unit, and the association has a say over roofs and yards. The condo guide lists what boards ask for.
Gas, electric heat and running cost
Gas heats about 70% of Somerville homes, electricity about 19% and oil about 6%. The fuel you’re leaving decides the case for switching.
Electric heat
A unit on baseboard or wall heaters gets one unit of heat per kilowatt-hour. A heat pump moves two to three on a typical winter day, and Eversource’s winter heat pump rate cuts both distribution and transmission charges from November through April.
Gas heat
Gas is cheaper per unit of heat, so the reasons to switch are usually central cooling, an old boiler, or a renovation. We put the running cost on your actual rates; see the ducted vs ductless guide for the comparison with wall units.
The electrical side
Every unit in a Somerville two-family has its own meter and panel, and older ones can be small. We do a load calculation on your panel at the first visit, counting any baseboard or wall heaters that come out.
When the service has to grow, our typical range for an upgrade is $3,000 to $6,500, and Eversource sets the date for the new connection. Meter banks shared with other owners need their agreement too. See panel upgrades.
Rebates, rates and permits for Somerville houses
Inspectional Services issues the sheet metal, electrical and building permits for a ducted job. Gas comes from National Grid or Eversource depending on the street.
| What | The Somerville figure |
|---|---|
| Heat pump permit applications, Nov 2021 to Oct 2026 | 871, of which 356 sheet metal |
| Energy code | Specialized stretch code since July 1, 2023 |
| Fossil-fuel-free program | Not selected; gas backup allowed |
| Electric utility | Eversource |
| Homes in two-to-four-unit buildings | 55.2% |
Mass Save’s whole-home rebate covers replacing gas, oil or electric heat when the old system comes out. The three-decker guide and the cost guide explain how floors and prices add up.
What to expect on a Somerville job
The first visit measures each floor you own, maps the attic, closets and basement for routes, checks the panel and the meter bank, and photographs the outdoor spot from the street.
- Written estimate: equipment with capacity at 5°F, duct work, electrical, permits, rebate path and price, per floor.
- Owner sign-off: the other owners or the association approve shared spaces and yards before we file.
- Install, usually four to eight working days per floor depending on new ducts.
- Commissioning: pressure test, vacuum below 500 microns, charge by weight, airflow and static measured, controls set.
Cambridge next door runs a fossil-fuel-free ordinance; Medford to the north allows gas backup, as Somerville does.