What Somerville renovated this year: 7,174 building permits, by the numbers
Bathrooms, roofs, kitchens and heat pumps lead the list. Here's what a year of City permit data says about Somerville homes — and what it means for your project.
Mateus MagnoLicensed Construction Supervisor · October 19, 2026 · 3 min read
Every renovation in Somerville leaves a paper trail: a permit filed with the City's Inspectional Services Division (ISD). The City publishes those permits as open data, and I track them on a live map for my own work. So I asked a simple question: what did Somerville actually renovate in the last 12 months?
The big picture
- 7,174 permits went through the building department between October 2025 and October 2026 — roughly 450 a month.
- 2,538 were building permits, 2,091 electrical, 808 plumbing, 640 gas, and 316 sheet-metal (ductwork) permits.
- 254 projects reached a Certificate of Occupancy — the finish line for new units and major renovations.
- 94 demolition permits were filed, a sign of how much rebuilding is happening alongside renovation.
What people are fixing
When you read the permit descriptions, the same jobs come up again and again:
- Bathrooms — 864 permits. The most common project in the city, by a wide margin.
- Roofs — 666. Somerville's housing is old; roofs are wearing out on schedule.
- Kitchens — 652. Often paired with a bathroom in the same permit.
- Heat pumps and HVAC — 557. The switch away from oil and gas is real and steady.
- Basements — 505. Finished basements are one of the few ways to add living space without changing the building's footprint.
- Insulation and weatherization — 441. Much of it through Mass Save.
- Then decks and porches (387), windows (312), siding (211), solar (207) and accessory dwelling units (111).
Where it's happening
The busiest neighborhoods by permit count were Spring Hill (1,195), Union Square (1,037), Winter Hill (851), Davis Square (781) and East Somerville (632), followed by Magoun Square, Hillside, Porter Square, Ball Square and Teele Square. If it feels like every other house on your street has a dumpster out front, you're probably right — 168 street-dumpster permits were issued this year.
What this means for your project
- Book early. With about 450 permits a month, good licensed trades are busy. Spring and early summer fill up first.
- One project, several permits. A typical kitchen or bath needs a building permit plus electrical, plumbing and sometimes gas permits — each pulled by the licensed trade doing that work. Your builder should coordinate all of them.
- Plan the "while we're in there" items. Heat pumps, insulation and electrical upgrades are easiest to add while walls are open — and many qualify for Mass Save incentives.
- Expect inspections. Rough and final inspections are part of every permit. They protect you; schedule them into the timeline.
How I counted
I used the City's permit dataset for the 12 months up to October 19, 2026, kept only building-department (ISD Building) records, and searched each permit's description for keywords (bath, kitchen, roof, heat pump, and so on). A permit that mentions a kitchen and a bathroom counts in both. Neighborhoods are the ones the City assigns to each address.
Planning a project in Somerville? Talk to me — I'll tell you which permits it needs and how long they're taking right now.
Mateus Magno is the founder of Magno & Co — a licensed Massachusetts Construction Supervisor (CS-123658), registered Home Improvement Contractor (HIC #220484) and certified Lead-Safe Renovator Supervisor who has renovated and managed over $3 million in projects across Greater Boston.
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