How Much Does a Building Permit Cost in Boston?

Permit Cost by Project

Do You Need a Permit?

Boston's Inspectional Services Department charges building permits on the estimated cost of work. The short form, for "minor alterations, repairs, or replacements that do not change the structure or use", is a $20 application fee plus $10 per $1,000. The long form, for work that changes a building's structure or use, is $50 plus $10 per $1,000. The city's own issued-permit records show the $10 is charged for each started $1,000, so a $7,100 deck on a long form is $130. These rates come from the ISD Building Fees schedule dated May 15, 2023, and the live boston.gov permit pages print the same numbers.

On the short form, a $12,000 re-roof is $140 and a $25,000 one $270. Replacing $10,000 of siding is $120, and $8,000 of windows $100.

Trade permits are separate. Plumbing is $20 plus $5 per fixture. Electrical is $20 plus $0.25 per amp for a new or upgraded service, so a 200-amp panel is $70; with no service change it is $20 plus $1 per fixture, plug or outlet, so a single EV charger outlet is $21. Gas is $20 plus $5 per appliance, with boilers, heaters and furnaces priced at $50 each plus $0.09 per 1,000 BTU. Sheet metal is $20 plus $25 per 200 linear or square feet.

Our remodel figures count a typical job: three plumbing fixtures, and six electrical fixtures and outlets for a bathroom or twelve for a kitchen. On that count a $15,000 bathroom comes to $231 and a $25,000 kitchen to $337. A gas water heater takes a $25 plumbing permit and a $25 gas permit, $50 in all, which is how the City's own issued permits are charged. Solar takes a short form and an electrical permit, each $20 plus $10 per $1,000, so a $15,000 system is $340. The central air figure is pending ISD's confirmation of whether the air-handler connection needs a sheet-metal permit.

The Massachusetts Residential Code (780 CMR 51, R105.2) lists what needs no building permit: one-story detached sheds and playhouses up to 200 square feet; fences not over 7 feet; retaining walls up to 4 feet that do not support a surcharge; sidewalks and driveways; painting, papering, tiling, carpeting, cabinets, countertops and similar finish work; prefabricated pools under 24 inches deep; playground equipment; small window awnings; and decks of 200 square feet or less, no more than 30 inches above grade, not attached to the house and not serving a required exit door.

Ordinary repairs need no permit either (R105.2.2), but cutting away a wall, removing a structural beam or changing egress does. Electrical, plumbing and gas work need their own permits even when the building work is exempt.

Boston's fee schedule charges a "DOUBLE FEE" when work has been started without the required permit, or when the estimated cost was understated.

The city can also stop the work until a permit is issued. Property sales are where unpermitted work surfaces most often, and the sale can stall while you get approval after the fact. Pull the permit first.

Under 780 CMR 51 R105.5, a permit becomes invalid if work does not start within 180 days of issuance, or if work is suspended or abandoned for 180 days. The building official can grant written extensions of up to 180 days each, requested before the permit expires with justifiable cause. Boston's long-form page puts it as "You must start work within six months of your permit being issued."

File the application as soon as the contract is signed.

On a short or long form, a homeowner can apply only for work they will do themselves in a one- or two-family, owner-occupied home. Otherwise the licensed contractor applies, in their own name, with a copy of their license, a current certificate of liability insurance and the signed contract.

Plumbing, gas and sheet-metal permits are available to licensed contractors only. A homeowner cannot apply for them.

Red flag. If your contractor asks you to pull the permit, ask why. Have the contract state who pulls each permit.

Boston does not use the standard International Building Code as published. Massachusetts writes its own amended code, 780 CMR, with a separate residential volume (780 CMR 51) whose permit rules were amended effective October 11, 2024.

The fee structure is unusual too: one valuation rate for the building permit, and trade permits priced by what is installed rather than by project cost. A small plumbing job with two fixtures is $30 whatever it costs; a new 200-amp service is $70.

The catch is counting. A kitchen remodel's trade fees depend on how many fixtures, outlets and gas appliances go in, which is why this page states the count behind each remodel total.

How much does a building permit cost in Boston?

It depends on the form. A short form is $20 plus $10 per $1,000 of estimated cost, so a $12,000 re-roof is $140. A long form, for structural work, is $50 plus $10 per $1,000, so a $12,000 job is $170. Trade permits are extra and priced by fixture, outlet, appliance or amp.

Do I need a permit to replace a water heater in Boston?

Yes. The plumbing permit is $20 plus $5 for the water heater, $25. A gas water heater also needs a gas permit at $20 plus $5 per appliance, another $25, so $50 in all. The City's issued permits charge it that way.

Do I need a permit to build a deck in Boston?

Usually. A deck needs a long-form building permit unless it is 200 square feet or less, no more than 30 inches above grade, not attached to the house and not serving a required exit door. A $7,100 deck is $50 plus $80, or $130.

Do I need a permit for electrical work in Boston?

Yes, electrical work needs a separate electrical permit in Boston. A new or upgraded 200-amp service is $20 plus $0.25 per amp, $70. Work with no service change is $20 plus $1 per fixture, plug or outlet.

Why are Boston plumbing permits so cheap compared to other cities?

Boston prices plumbing by the fixture, not the project cost: $20 plus $5 per fixture. A job with two fixtures is $30 whatever it costs. Plumbing permits go only to licensed plumbers.