Key Takeaways
•The short answer: The Boston Globe reports that Mayor Wu renewed a proposed fee on real estate sales over $2M. Boston.gov describes it as up to 2% on transactions over $2M, with the first $2M exempt. A home that stays put would owe no transfer fee under it. Higher tax rates may raise a tax bill.
•What changed: In April 2026, Mayor Wu renewed a proposed transfer fee, per the Boston Globe. On June 23, 2026, the Supreme Judicial Court (SJC) ruled that the statewide rent-control question could not go on the November 2026 ballot, per WBUR. GBH News reported higher Boston tax rates in December 2025.
•The real math: Price signals are mixed. Zillow's Boston city average home value was down 1.6% from a year earlier (updated Sept. 30, 2026), while Redfin put Boston's median sale price for the three months ending September 2026 up 1.9%. Boston also raised its tax rates (per GBH News), and insurance and repairs add to the yearly cost of owning.
•What the numbers test: An accessory dwelling unit (ADU) is a small second unit on a property. Whether its rent covers the added costs depends on the property's numbers.
Does the $2M Transfer Fee Affect My Home?
As of October 22, 2026, probably not.
•The transfer fee: The Boston Globe reported that on April 30, 2026 Mayor Wu signed her renewed proposal for a fee on real estate sales over $2M. Boston.gov describes a fee of up to 2% on real estate transactions over $2M, with the first $2M exempt. The City Council passed the petition on April 15, 2026. Boston.gov says it moves next to the State Legislature, and the Globe said it also needs the Governor. It would apply only when a property sells, and it is a proposal.
•The rent-control ballot ruling: On June 23, 2026, the Supreme Judicial Court ruled that the statewide rent-control question could not go on the November 2026 ballot because it included a religious-facilities exemption (WBUR, read Oct. 23, 2026). Supporters have hinted they could try again in 2028.
•Higher property taxes: GBH News reported on December 11, 2025 that the City Council approved Boston's property tax formula for the coming year. Boston's Assessing Commissioner said it means residential property is taxed at $12.40 per $1,000 of value, up from $11.58. WBUR reported that the vote effectively locks in a 13% increase for homeowners in the coming year, about $780 on average.
The proposed fee would apply only when a property sells, so it would not apply to a home that stays put. Boston raised its tax rates in December 2025, per GBH News, which can raise a tax bill.
When values are flat or slow and ownership costs grow, appreciation covers less of the yearly cost.
How Did Boston Owners Get Squeezed?
In inflation-adjusted terms, 57 Greater Boston communities had median single-family prices under $500,000 in 2015. As of 2025, only 3 did: Brockton, Wareham, and Halifax. That comes from the Boston Foundation's Greater Boston Housing Report Card 2025, prepared by Boston Indicators (November 2025).
New construction has not filled the gap. Massachusetts permitted just 14.3K housing units in 2024, per Census building permit data charted in that report. That is far below the early-1970s peak of about 53,000 (in 1971) and below 2021's total of about 19,900.
The rule changes came quickly:
•Aug. 1, 2025: The Massachusetts broker-fee law took effect (Mass.gov: the person who hires the broker pays the fee).
•December 2025: Boston raised its tax rates, per GBH News.
•April 2026: The $2M transfer-fee proposal returned.
•June 23, 2026: The SJC ruled the statewide rent-control question could not go on the November 2026 ballot.
What Does the Fall 2026 Math Look Like If You Stay?
Two public sources, read October 23, 2026, show different pictures of Boston prices. Zillow's Boston city page showed an average home value of $761,236, down 1.6% over the past year (updated Sept. 30, 2026). Redfin put Boston's median sale price at about $841,000 for the three months ending September 2026, up 1.9% from the same period a year earlier. The two use different methods, so they can move in different directions.
Property type matters too. In July 2026, single-family homes sold at a median of $1,107,500 after 34 days on the market, and condos at $777,500 after 45 days. Source: MLS PIN data via Repliers, July 2026.
A simple owner worksheet has three lines:
1. Two dated readings. Zillow's Boston city average home value was down 1.6% from a year earlier (updated Sept. 30, 2026). Redfin's Boston median sale price for the three months ending September 2026 was up 1.9% from a year earlier. They are different measures, so they are two readings, not a forecast.
2. Yearly costs. Any tax increase, insurance, repairs, and maintenance.
3. The gap. If costs eat most of the gain, appreciation is not doing enough work.
The worksheet uses a home's likely selling price, not just its assessed value. Boston sets the assessed value to calculate the tax bill, and it can differ from market value.
Mortgage rates are part of the math. Freddie Mac's survey put the 15-year fixed average at 6.71% and the 30-year fixed average at 7.40% on Oct. 15, 2026. A year earlier, the 15-year fixed average was 5.52%. An owner with a lower locked-in rate who sells and buys again would trade that rate for a rate in that range.
A low rate keeps your mortgage payment steady. It does not freeze taxes, insurance, or repair bills. That is why some owners look at rental income, while others decide the gap is small enough to absorb.
Where Does an ADU Fit for Boston Homeowners?
An ADU can be a small second home on your lot or a unit inside your house. It adds a unit that can be rented, and its rent can be compared with taxes, insurance, and other ownership costs.
WBUR reported that the SJC ruled the statewide rent-control question could not go on the November 2026 ballot, so that question will not be on this November's ballot. Supporters have hinted they could try again in 2028. A rent estimate for an ADU can use what similar nearby units rent for, and a lower estimate shows how much cushion the numbers have.
The rent test depends on:
•Whether your lot and layout qualify with the City of Boston.
•What construction or conversion will cost.
•How long permitting may take.
•What similar units nearby actually rent for.
•Landlord duties, which add work and cost.
A new unit can raise your assessed value, and with it your tax bill. One test: does yearly rent exceed the added tax plus loan or construction costs, upkeep, and vacancy? If it does not, the ADU adds to the gap instead of closing it.
What Landlord Rules Apply to an ADU Rental?
Three rules shape the rental math: broker fees, application fees, and security deposits.
•Broker fees: Under the Massachusetts broker-fee law that took effect Aug. 1, 2025, the person who hires the broker pays the fee (Mass.gov, checked Oct. 23, 2026). NBC Boston reported in September 2026 that renters who believe they were charged a broker fee by a broker they did not hire can file a complaint with the Attorney General's Office.
•Application fees and deposits: M.G.L. c.186, s.15B limits what a landlord may require at or before the start of a tenancy. The list is the first month's rent, the last month's rent, a security deposit of no more than one month's rent, and the purchase and installation cost for a key and lock. Application fees are not on that list. The statute also lets state regulations authorize an optional fee in place of a security deposit, capped at one month's rent in total. A deposit must be returned within 30 days after the tenancy ends.
A landlord's costs can include any tenant-finding help, handling deposits under the 30-day return rule, and a repair cushion. Rent estimates can come from comparable nearby listings, and cost estimates from contractor bids.
What Are the Arguments Against Adding Rental Income?
"Renting may cost less than owning, so selling may look better."
For some owners, the numbers favor selling. Renting also means no landlord duties or construction risk.
But selling has costs: transaction fees and moving costs. Profit above the federal home-sale exclusion can be taxed as capital gains; the current limit is in IRS Publication 523. A buyer who buys again pays the mortgage rates of the day.
An owner can set the full after-tax result from selling beside the long-term value of staying. Whichever figure is higher is what the numbers favor in that case.
"An ADU may cost too much."
Also fair. Construction, permitting, design, financing, and delays can eat into returns, and a rent estimate built on optimistic assumptions can overstate them.
The June ruling did not make ADUs profitable. It took one question off this fall's ballot. Each property still needs its own numbers.
Which Situations Add Risk to a Move?
These situations add risk:
•Your home sells for more than $2M. Boston.gov describes the proposed fee as up to 2% on real estate transactions over $2M, with the first $2M exempt. It would apply only if it becomes law.
•You own a condo. Association rules, layout, or shared systems may block an ADU.
•You do not want landlord duties. Screening, repairs, and compliance take work.
•You cannot absorb upfront costs. Even a smart project can strain cash flow before rent starts.
Zillow's Boston city average home value was down 1.6% from a year earlier (updated Sept. 30, 2026), while Redfin's Boston median sale price for the three months ending September 2026 was up 1.9%.
On the Zillow measure, that could mean little or no appreciation cushion; Redfin's figure points the other way. If the cushion is small, rent has to cover a project's cost, which is what the rent test above measures. A costly project in a flat market carries more risk.
Which Numbers Can Boston Owners Review Before Year-End?
1. A comparison of the latest tax bill with last year's.
2. Two dated readings: Zillow's -1.6% past-year change in Boston's average home value (updated Sept. 30, 2026) and Redfin's +1.9% change in the median sale price for the three months ending September 2026 (different measures, so a rough range).
3. Yearly taxes, insurance, maintenance, and repairs.
4. ADU eligibility for the lot, confirmed with the City of Boston.
5. Construction cost, from actual contractor bids rather than estimates.
6. Rent modeled under current broker-fee and deposit rules, including any added tax from the new unit.
7. The transfer-fee proposal matters only to a home that sells for more than $2M.
Boston.gov says the first $2M of a sale would be exempt from the proposed fee. A fee on real estate transactions would apply only when a home sells. For an owner who stays, ownership costs are the numbers that change.
So if you want to stay, the question is practical:
Can your property help pay for itself, or is the gap small enough to absorb?
Send me the address and I will run the numbers on a hold-versus-sell comparison and an ADU rent test for that property.
This article is general information, not legal or tax advice. Talk to your CPA and attorney about your own situation.
