Here’s the short answer. When you buy a two-family or triple-decker in Boston, you’re buying a home and a small rental business at once. If you’ll live in one unit, you can use owner-occupied financing, including FHA, and the lender may count rent from the other units toward your income. You also step into the seller’s shoes as a landlord. That means taking over existing leases, security deposits and last month’s rent, along with Massachusetts obligations like the lead law and Boston’s annual rental registration. There’s no rent control in Massachusetts today, but tenant protections are strong, so do your homework before you sign.
At a glance
- FHA minimum investment
- 3.5 percent
- Of the property’s adjusted value
- FHA rent counted
- 75 percent
- Without a rental history on the property
- Deposit notice to tenants
- 45 days
- After the security deposit transfers to you
- Lead law compliance
- 90 days
- After taking ownership, if a child under six lives in a unit
- Boston rental registration
- July 1
- Every year
- Rent control
- Prohibited
- On most private residential property (chapter 40P)
Where two-families and triple-deckers are
Wood triple-deckers (three stacked units, usually with porches front and back) and two-families are the typical housing in many parts of Boston. You’ll find them in Dorchester, South Boston, East Boston, Jamaica Plain, Roslindale, Mission Hill, Roxbury, Hyde Park, Mattapan, Allston and Brighton. Just outside the city they’re common in Somerville, Cambridge, Chelsea, Everett, Malden and Revere. Two-families are also common in Medford, Arlington, Belmont, Watertown, Waltham and Quincy. Many buildings in these areas have already been split into condos, so check whether a listing is a whole building or a single unit.
Owner-occupant or investor
This one decision drives your financing, your down payment and some of your tax treatment:
- Owner-occupant. You live in one unit as your principal residence. That opens up owner-occupied loan programs, including FHA. In Boston, an owner-occupant may also qualify for the residential exemption on the property tax bill. The city’s assessing department explains eligibility and deadlines, so ask how it applies to a multi-unit building.
- Investor. You won’t live there. Investment property loans have their own down payment and reserve rules, and owner-occupant programs such as FHA aren’t available. Check the terms with your lender before you shop.
If you start out as an owner-occupant, be honest about your plans. Owner-occupied loans come with an occupancy commitment.
Financing: what FHA and Fannie Mae allow
FHA. FHA insures owner-occupied homes of one to four units. Its Single Family Handbook (4000.1) requires a Minimum Required Investment of at least 3.5 percent of the property’s adjusted value. Loan limits are higher for two-, three- and four-unit homes than for one-unit homes, and they vary by county, so look up the current figure for Suffolk County or wherever you’re buying on HUD’s FHA mortgage limits page.
Triple-deckers face an extra test.
To help you qualify, FHA lets lenders count rent from the other units. If you don’t have a rental history on the property, the current handbook (updated August 12, 2026) counts 75 percent of the lesser of the appraiser’s fair market rent or the rent in the lease.
Conventional (Fannie Mae). Fannie Mae also finances two- to four-unit principal residences. Its Selling Guide lets lenders count rent from the units you don’t occupy, documented with leases and the appraisal. The amount counted may be limited by whether you currently have a housing payment and whether you have property management experience. For example, positive rental income can be used only if you have at least 12 months of property management experience. Down payment and reserve rules depend on the number of units, so ask your lender for the current Fannie Mae eligibility matrix numbers for your building.
Massachusetts also has state and nonprofit programs for buyers. Our first-time home buyer guide explains them; check each program’s current rules on whether it covers multi-family homes.
Existing tenants, leases and deposits
In a sale, tenants generally stay, and a written lease normally keeps going after the building changes hands. Before you sign the Purchase and Sale Agreement, ask for:
Ask for these before the Purchase and Sale Agreement
- A rent roll showing each unit’s rent, lease start and end dates, and who lives there
- Copies of every lease and tenancy-at-will agreement
- Security deposit amounts, the bank where each is held, and interest records
- Any last month’s rent collected
- Lead paint letters of compliance or interim control, and any lead disclosure forms tenants signed
- Any pending notices, court cases or code violations
Rent control: the current law
Massachusetts General Laws chapter 40P prohibits rent control on most private residential property. Publicly owned, publicly subsidized and federally assisted housing are excluded, and some of those units carry their own rent rules. Proposals to change the law come up from time to time.
Lead paint: the Massachusetts lead law
Most triple-deckers were built long before 1978, so the lead law matters here:
- At purchase. For pre-1978 homes, the seller and agents must give you the Property Transfer Lead Paint Notification before you sign a Purchase and Sale Agreement. Under the federal disclosure rule you then get a 10-day opportunity for a lead inspection or risk assessment, which the parties can change, or you can waive, in writing.
- As an owner. If a child under six lives in a unit, the owner must have it inspected and brought into compliance. That means a letter of full compliance, or a letter of interim control while work is pending. A new owner has 90 days after taking ownership to comply (M.G.L. c. 111, § 197).
- No discrimination. You may not refuse to rent to families with children under six because of lead paint, or evict or decline to renew them for that reason.
- Help. The state offers an income tax credit for deleading costs. Check mass.gov for the current amount.
A valid compliance letter on each unit is worth asking for, and pricing in, during your negotiation.
Smoke and carbon monoxide certificates
Massachusetts requires the seller to equip a residential building with approved smoke detectors when it’s sold. The local fire department also inspects for carbon monoxide alarm compliance at sale. In Boston, the Fire Prevention division handles these inspections for residential sales. On a multi-family, every unit and the common areas have to pass. Sellers usually arrange this before closing, but confirm in the Purchase and Sale Agreement who is responsible.
Inspections: what to look at in a multi-family
A home inspection on a two- or three-family covers more ground. Ask your inspector to see every unit, and make sure the tenants get proper notice. Focus on:
What to inspect in a multi-family
- Heating systems: whether each unit has its own system or they share one, plus their age and type
- Porches and egress: rear porches and stairs, and second ways out of upper units
- Electrical and plumbing: service capacity, the panels for each unit, and how the water and gas are metered
- Roof, gutters and exterior wood and paint (also relevant to the lead law)
- Basement: water, the foundation, and any finished space
- Permits: work done without permits, and whether the legal number of units matches how the building is actually used. Your attorney can help confirm the legal occupancy.
Condo conversion considerations
Some buyers plan to convert a two- or three-family into condos later. To do that, you’ll need a master deed and condo documents prepared by an attorney, and permits for any construction. Boston’s Condominium and Cooperative Conversion Ordinance applies to properties built before December 1983 with four or more rental units. It requires a one-year notice to tenants, relocation help and a city conversion plan and permit, so most two- and three-families aren’t covered by it today. The city has proposed extending it to smaller buildings, so check the current version before you plan a conversion. Lenders, zoning and the building’s condition can still get in the way, so don’t build your purchase price around a conversion until your attorney has reviewed it. If you’re weighing a condo instead, read buying a condo in Boston.
Insurance and Boston landlord registration
A building with rental units needs a policy written for that use. Tell your agent how many units are rented and whether you live there. Ask about liability coverage, loss of rents, and coverage for the units’ systems. Have your tenants carry their own renters insurance.
The City of Boston requires rental properties to be registered every year, with a July 1 deadline, and says it will inspect registered properties at least once every five years, though owner-occupied buildings with six or fewer units are exempt from those routine inspections.
Closing costs and next steps
Multi-family purchases close with an attorney, like any Massachusetts purchase, and go through the same offer and Purchase and Sale steps. See making an offer in Massachusetts and Massachusetts closing costs.
This guide is general information, not legal, tax or lending advice. Confirm the details with a real estate attorney, your lender and a tax advisor.
If you’re looking at two-families or triple-deckers and want help comparing buildings and areas, The Pettengill Group can walk you through it. Start a search or, if you already own one, get a home value estimate.