




21 Hosmer St, Mattapan, MA, 02126
About This Home
A rare, fully turn-key Mattapan multi-family delivering scale, flexibility, and immediate income in a high-demand Boston market. This oversized 3-family features three expansive 3 bed/1 bath units, each with layouts that can easily function as 4-bedroom apartments maximizing rental potential. Designed for today’s buyer, the property offers central air, updated electrical, hardwood floors, modern kitchens & baths, new siding, newer rubber roof, & decks throughout. The building is well-maintained with a strong in-place rent roll, creating a true plug-and-play investment or an ideal opportunity for an owner-occupant to offset their mortgage with substantial income. ***NOTE***Additional upside: the identical neighboring property at 19 Hosmer St is also available...purchase one or secure both for a scalable $240K+ gross annual rent play. Positioned near public transit, retail, and many amenities, this is a high-performing Boston multi-family with long-term appreciation and income growth!
Getting Around
Schools
Construction
Condition
- Year built: 1900
Materials
- Foundation: Other
- Roof: Shingle
- Construction materials: See Remarks
Type & Style
- Home type: MultiFamily
- Property subType: 3 Family
Interior
Basement
- Has basement: Yes
- Basement: Full
Bedrooms & Bathrooms
- Bedrooms: 9
- Bathrooms: 3
- Full bathrooms: 3
Features
- Flooring: Hardwood
- Finished area above ground: 4,056
Interior Area
- Total structure area: 4,056
- Total interior livable area: 4,056 sqft
Property
Details
- Parcel number: W:14 P:04135 S:020,1358746
- Zoning: R3
Features
- Patio & porch: Porch
Lot
- Lot size: 4,225 sqft
- Features: Other
Parking
- Total spaces: 6
- Parking features: Off Street
- Uncovered spaces: 6
Climate Risk is Financial Risk
Every home has a financial story beyond the listing price. Below, you’ll see the climate risks that could affect this property — and in Bills & Affordability, how those risks may influence repairs, insurance, utilities, and long-term value.
Biggest Threats for This Home
- Cold Wave
- Heat Wave
- Lightning
- Tsunami
How This Home’s Risks Compare
FEMA Declared Disasters Across Massachusetts Counties
Understanding the Costs
Financial advisors generally recommend spending no more than 30% of your gross household income on housing costs. In practice, many households stretch to 35% or beyond — especially in high-cost markets.
Estimated Costs Today
| Monthly | Annual | |
|---|---|---|
| Mortgage | $6,568 | $78,816 |
| Home Insurance * | $513 | $6,156 |
| Property Taxes | $1,257 | $15,084 |
| Electricity | $799 | $9,597 |
| Total | $9,137 | $109,644 |
Income You'd Need if You Spent...
Massachusetts FAIR Plan Programs
How Costs Could Change Over Time
Climate risk is quickly impacting all of the major home ownership costs. Adjust the growth rates and percentage of income spent on housing below to see how your housing costs could change over the next 10 years — and what income you'd need to keep up.
Comparing Against the Market
Price Per Sq Ft
vs Other Active Listings
Avg $/sqft
vs Homes Sold Last Month
Median $/sqft
Current Market Trends
Median Price Per Square Foot
The median price per square foot of homes sold in this area each month. Compare this to this listing's price per square foot to gauge whether the home is priced in line with recent sales.
Historicals for This Listing
Zestimate History ($/sqft)
Price History
| Date | Event | Price |
|---|---|---|
| 2026-06-04 | Price change | $1,299,000 |
| 2026-05-14 | Listed for sale | $1,350,000 |
| 2014-05-12 | Sold | $300,000 |
| 2007-08-24 | Sold | $335,000 |
