From Back Bay pilings to Dorchester triple-deckers: what a buyer’s agent checks before writing an offer in Boston.
Boston is a city of distinct nineteenth- and early-twentieth-century building eras, and the era usually tells a buyer’s agent what to worry about. Back Bay and much of the South End were built from the 1860s through the 1880s on filled tidal land, with masonry rowhouses resting on wood pilings driven into that fill; the piles stay sound only while groundwater covers their tops, and a falling water table exposes and rots them. Dorchester, Roxbury, Jamaica Plain, East Boston, South Boston and Allston-Brighton are instead dominated by wood-frame triple-deckers built roughly 1890 to 1930, where the recurring issues are knob-and-tube wiring, undersized electrical panels, and buried heating-oil tanks left over from decades of oil heat. Newer construction clusters in the Seaport and in condo conversions citywide, which mostly avoid the above but still sit on the same filled or low-lying ground.
Flood exposure is real and neighborhood-specific rather than citywide. East Boston, Charlestown, the North End and downtown waterfront, South Boston around the Fort Point Channel and Moakley Park, and low-lying stretches of Dorchester along Morrissey Boulevard sit in or near FEMA’s mapped coastal high-risk zones, and the city’s neighborhood-by-neighborhood Coastal Resilience plans (completed 2017-2022) project sea-level-rise and storm-surge exposure well beyond the current FEMA lines. Riverine flooding along the Charles is a secondary but real concern for low ground near the river’s edge. Any offer near these areas should be checked against both the current FEMA panel and Boston’s own resilience mapping, not just one or the other.
For the masonry rowhouse neighborhoods built on piles — chiefly Back Bay, the South End, Bay Village, and parts of Beacon Hill and the North End — the nonprofit Boston Groundwater Trust runs a network of more than 800 monitoring wells and publishes readings by area; a buyer’s agent should pull the nearest well’s recent trend and ask sellers directly about any prior piling inspection or underpinning work, since drought years have measurably lowered levels in parts of the city. Worth flagging to buyers separately: traffic and noise from the Central Artery/I-93 corridor, the Mass Pike (I-90) trench through Back Bay, Fenway and the Allston interchange area, and Logan Airport flight paths affecting East Boston, South Boston and parts of Winthrop and Chelsea.
Boston’s property tax picture has one feature most Massachusetts towns lack: a residential exemption shielding a slice of assessed value from tax for owner-occupants, set at the state maximum of 35% for FY2026 (worth up to $4,353.74 against a $12.40-per-$1,000 residential rate). It is not automatic and does not transfer to a buyer, and it carries an annual filing deadline (April 1) — anyone converting a purchase to owner-occupied use, or buying from a seller who carried the exemption, needs to budget for what the bill looks like without it until they file. The city also carries the Community Preservation Act’s 1% surcharge, in place since a 2016 ballot vote.
Utility and regulatory setup differs from most Massachusetts towns too: water and sewer are run by the Boston Water and Sewer Commission (BWSC), an authority separate from City Hall, which also runs a no-cost private lead-service-line replacement program worth asking about in pre-1950 buildings. Zoning and large-project review moved out of the long-standing Boston Redevelopment Authority/BPDA structure into a new, mayor-controlled Planning Department on July 1, 2024, though Article 80 large-project review itself is still being modernized rather than replaced. Deeds record at the Suffolk Registry of Deeds, and because most of the city’s housing predates 1978, lead paint compliance is a near-default diligence item here, not an edge case.
The primary sources for Boston records. Deeds record at the Suffolk Registry of Deeds (Boston).
| Office / tool | What it's for |
|---|---|
| Assessing Online / Property Lookup (City of Boston Assessing Department) | Search by address or parcel ID for assessed value, ownership, and FY2026 tax data. |
| Boston Tax Parcel Viewer (city GIS) | |
| Inspectional Services Department (ISD) — permits, code violations, and historical permit records | Active permit search is at permitfinder.boston.gov; historical paper records are indexed separately (see ISD’s how-to page). |
| Zoning Viewer (Boston Planning Department) | Interactive map of zoning districts and dimensional requirements; the codified text is on Municode. |
| Boston Public Health Commission (functions as the city’s board of health) | Handles lead paint, housing sanitary code, and public health enforcement; a state-chartered commission, not a standard local board of health. |
| Boston Conservation Commission (wetlands, floodplain, Boston Wetlands Ordinance) | |
| Boston Water and Sewer Commission (BWSC) | Independent authority, not a city DPW — handles all water/sewer accounts, connections, and the lead service line replacement program. |
| MassGIS MassMapper (statewide parcel viewer) | Statewide parcels, wetlands, and zoning-adjacent layers |
| Suffolk Registry of Deeds — online land record search | suffolkdeeds.com, massrods.com, and masslandrecords.com/Suffolk all blocked automated verification this session — the latter returned HTTP 200 but served an Incapsula challenge page rather than real content, not a genuine result. The district’s existence and address were confirmed via the Secretary of the Commonwealth’s registry directory instead; search in an ordinary browser or visit in person. |
| FEMA Flood Map Service Center | Official flood-zone determination by address |
Search Boston’s Permit Finder and the Inspectional Services Department’s historical permit records for the address. Unpermitted conversions and additions are common in triple-deckers and rowhouses that have been split into more units or condos over the decades.
Look up the parcel on the FEMA Flood Map Service Center, then compare it against Boston’s neighborhood Coastal Resilience Plans (2017-2022) for East Boston, Charlestown, South Boston, Dorchester, and downtown/the North End — the city’s own sea-level-rise projections extend past the current FEMA lines.
In Back Bay, the South End, Bay Village, and parts of Beacon Hill and the North End, pull the nearest well reading from the Boston Groundwater Trust and ask the seller about any piling inspection or underpinning history; falling groundwater exposes and rots the wood piles these buildings rest on.
Most Boston housing predates the 1978 federal lead ban. Ask for the most recent lead compliance or deleading documentation, especially in multi-family buildings where a child under six could reside, since Massachusetts’ Lead Law imposes strict-liability obligations on owners.
Boston’s residential exemption (35% of assessed value for FY2026, worth up to $4,353.74) is not automatic and does not transfer at sale. A buyer who will owner-occupy must file with the Assessing Department by the annual April 1 deadline; a buyer who won’t (e.g., an investor) should budget for the un-exempted bill from day one.
Water and sewer in Boston are billed and maintained by the Boston Water and Sewer Commission, not the city. Confirm the account is current and ask whether the property’s private service line is lead (common in pre-1950 construction) and eligible for BWSC’s no-cost replacement program.
Use the Planning Department’s Zoning Viewer to confirm the district and dimensional requirements, then check whether the building’s actual configuration (unit count, use, parking) is a legally permitted or grandfathered nonconforming condition — particularly for older buildings converted to more units than originally built.
Ask about heating history and consider an oil-tank sweep for pre-1980s triple-deckers and rowhouses that may have converted from oil heat. For parcels in historically filled areas (Back Bay, South End, Seaport, East Boston, South Boston) or near former industrial sites, checking MassDEP’s contaminated-site records is a standard diligence step, not a red flag in itself.
Yes — owner-occupants can exempt a portion of their home’s assessed value from taxation, set at the state maximum of 35% for FY2026 (up to $4,353.74 in savings against the $12.40-per-$1,000 residential rate). It is not automatic and does not carry over at sale; buyers who will live in the property must file their own application with the Assessing Department, and there’s an annual deadline (April 1).
FEMA’s coastal high-risk zones and the city’s own Coastal Resilience planning both point to East Boston, Charlestown, the North End and downtown waterfront, South Boston around the Fort Point Channel and Moakley Park, and low-lying parts of Dorchester along Morrissey Boulevard. Riverine flooding along the Charles is a secondary risk for low ground near the river. Flood risk varies block by block, so always check the specific parcel rather than the neighborhood’s general reputation.
Back Bay, the South End, and other nineteenth-century neighborhoods were built on filled land, with buildings supported on wood pilings driven into that fill. Those piles stay sound only while groundwater covers their tops; the nonprofit Boston Groundwater Trust runs more than 800 monitoring wells across the city specifically to track this risk, and drought years have measurably lowered levels in some areas. It’s a genuine structural-diligence item for these neighborhoods, not a niche concern.
The Boston Water and Sewer Commission (BWSC), a public authority separate from City Hall departments, handles billing, connections, and infrastructure. It also runs a no-cost program to replace private lead service lines in older buildings — worth asking about for anything built before 1950.
Yes — a large share of Boston’s housing stock predates the 1978 federal lead paint ban (the exact citywide percentage isn’t something we’ve verified precisely), and Massachusetts law imposes strict-liability deleading obligations on owners of properties where a child under six lives. Ask sellers for current lead compliance or deleading documentation, particularly on multi-family conversions.
When Fyts researches a Boston property, the workflow feeds Boston-specific context (flood waters, utilities, zoning sources, local ordinances) to its research agents and verifies the highest-stakes findings against primary sources. This page is general town research, not advice about a specific property — verify everything against the primary sources above.
One address in, one sourced go/no-go memo out. Your first report is free, no card required.