Short answer
Before a Massachusetts home is sold, the local fire department has to inspect the smoke and carbon monoxide alarms and issue a certificate of compliance. In Boston, Boston Fire runs the inspection and publishes its own consumer guide; in Brookline, Brookline Fire does. Requirements depend on the house's age and past permits, so read your department's guide and fix problems before booking the inspection.
Who issues the certificate and when to book
The certificate comes from the fire department in the town where the house sits, not from a private inspector. Boston Fire publishes its own consumer guide for the smoke and CO inspection required when one and two family homes are sold. Brookline's fire department runs the inspections required at sale in Brookline. Other towns have their own forms, fees and scheduling.
Book early. Departments schedule inspections days or weeks out, and a failed inspection means a second appointment. The certificate is usually valid for a limited period, so check your department's rules and time it close enough to the closing date. Your real estate agent and closing attorney will want a copy.
What the inspector looks for
Requirements depend largely on when the house was built and when it was last substantially renovated under a building permit. An older house that has never had major work may be allowed battery alarms in the right locations. A house built or renovated more recently may need hardwired, interconnected alarms with battery backup, because those were required when that work was permitted.
Inspectors generally check location, type, age and function. They press test buttons, look at manufacture dates, and confirm that alarms are where the rules require. Carbon monoxide alarms are needed in homes with fuel-burning equipment or an attached garage. Your department's guide is the authority, so read it before you start replacing anything.
- An alarm on every level, including the basement
- Alarms outside each sleeping area, and inside bedrooms where required
- Carbon monoxide alarms on each level where fuel-burning equipment or an attached garage is present
- Alarms within their manufacturer service life, judged by the date on the back
- Photoelectric or the correct type near kitchens and bathrooms where the rules call for it
- Hardwired alarms working on power and battery, and interconnected where required
Hardwired alarms to sort out before an inspection? We answer 24/7.
Call (617) 843-6591Common reasons houses fail
The most common failure is simple age. Smoke alarms carry a manufacture date and have a limited service life, often ten years, and many sellers find units older than that. A missing alarm in a finished basement or a new bedroom is another frequent problem. So is a CO alarm missing from a level, or a combination alarm installed where the rules want a separate type.
Hardwired systems fail for their own reasons: a unit removed and never replaced, a dead interconnect so one alarm sounds alone, a mix of brands that will not talk to each other, or a junction box with no alarm on it. Painted-over alarms, alarms behind a closed door and units installed too close to a kitchen or bathroom also show up on failure lists.
Battery alarms, hardwired systems and when an electrician helps
If your house only needs battery alarms, replacing them is a homeowner job: buy the right type, mount them where the guide says and note the dates. Many owners choose sealed ten year battery units so they do not chirp in the middle of a move. Keep the receipts and packaging in case the inspector asks.
Hardwired and interconnected systems are a job for an electrician. Replacing a hardwired alarm usually means matching the existing interconnect brand or replacing the whole set together. Adding a hardwired alarm in a new location means running cable through finished walls and ceilings, which is work that needs a permit. Massachusetts enforces the 2023 National Electrical Code with state amendments in 527 CMR 12.00, so new wiring follows current rules.
Two family houses, condos and renovated spaces
Multi-unit houses take more planning. In a two family, the inspector needs access to every unit, the basement and common hallways, so tenants have to be told and every door opened on the day. Alarms in common areas are part of the inspection, not just the alarms inside each apartment. Buildings with a central fire alarm system may be handled differently, so read the department guide for your building type.
Renovations matter too. A basement finished under a permit, a new bedroom in the attic or a kitchen remodel can trigger the newer alarm requirements for that part of the house, or for the whole house, depending on the scope and when it was permitted. If the house was renovated, find the permit dates before the walk-through, because they tell you which set of rules the inspector will apply.
A pre-inspection walk-through that saves a second visit
Two or three weeks before the inspection, walk the house with your fire department's checklist. Test every alarm. Read the date on the back of each one. Count the levels, including the basement and any finished attic, and note each bedroom. Look for fuel-burning equipment: furnace, boiler, water heater, gas range, fireplace or attached garage.
Then fix what you found before the appointment. Replace old units, add missing ones, and if the system is hardwired, have an electrician confirm that every alarm sounds when one is tested. On the day, make sure the inspector can reach every alarm, arrange access to every unit in a two family, and have your paperwork ready.
- Test every alarm and listen for interconnect
- Check manufacture dates and replace expired units
- Confirm coverage on every level and near each bedroom
- List fuel-burning appliances and the attached garage
- Arrange access to every unit and the basement
Where we can help
Smoke certificate questions from sellers
Generally yes, a unit sale also needs a certificate from the local fire department, and the rules can differ for units in larger buildings. Check your department guide, because some buildings have central fire alarm systems that change what is inspected.
Usually not. If hardwired alarms were required when the house was built or renovated, inspectors expect hardwired replacements. Replacing them with battery units is a common reason for failing.
It is valid for a limited time, and departments set their own rules. Check with your fire department and schedule the inspection close enough to closing that it does not expire.
The inspector lists what needs to change. You fix the items and book a reinspection, which usually carries another fee and another wait. A walk-through before the first visit avoids most second appointments.
In Massachusetts the seller normally arranges the inspection and the certificate before closing. Your agent or closing attorney can confirm what the purchase agreement says.
No, only the fire department issues it. An electrician can replace, add and test hardwired alarms so the house is ready, and pull any permit the wiring work needs.