Do I need an HVAC permit in Cambridge, MA? The mechanical permit, heat pump fees and why so many stay open

The Cambridge rule

All read 23 October 2026. The City's permit FAQ says plumbing, gas and wiring permits go only to state-licensed plumbers, gas fitters and electricians, and gives homeowners an exception only for building permits (ISD FAQ); it does not say who may pull a mechanical permit, so ask Inspectional Services (617-349-6100) before filing one yourself. On a gas-fired replacement the gas side is a licensed fitter's job regardless.

What a Cambridge HVAC job files

What Cambridge mechanical permits are for, counted from the City's Mechanical Permits open data on 23 October 2026 (1,554 permits issued October 2023 to September 2026, all building types; one permit can list several units):

Heat pumps appear on four times as many mechanical permits as furnaces. The permit type was Renovation on 725, Replacement on 447 and New on 382.

What it costs

From the City's Mechanical Fees page (no effective date printed):

A two-zone ductless system with one outdoor heat pump and two heads might be filed as $25.00 plus two $40.00 splits, $105.00, depending on how the installer counts the units; a gas furnace swap is $50.00 mechanical plus $50.00 gas. Starting first triples both.

What 1,470 Cambridge HVAC permits show

Cambridge HVAC permits often stay open: 53.4% Complete against 71.5% for electrical, and 16 of the 22 busy installers were under 70%. The 10th-percentile installer had 23.8% marked Complete; the 90th, 79.8%. Some of that is paperwork (a final never called), which is exactly what the City's $50.00 charge targets. Filing peaks in October (index 119). National prices are in HVAC replacement cost; counts by year on Cambridge permit statistics.

See every Cambridge HVAC installer by permits completed →

Before you hire

Look the installer up on the Cambridge HVAC list, and check the licenses a job needs in Cambridge contractor license lookup. The gas side of a furnace or boiler is in Cambridge gas line permit, the wiring in Cambridge electrical permit, past permits on your address in Cambridge building permit search, and other cities' rules in do I need a permit for HVAC replacement.

What this does not tell you

Cambridge publishes a status but no completion date, so our days to Complete are estimates, and an Active permit can mean a final that was never called. Our HVAC trade combines the mechanical and sheet metal permit files; the equipment counts above are from the mechanical file alone and include commercial buildings.