
21 Cottage Park Ave Cambridge — Photo 1 of 40
$3,599,950
Investment Analysis — 21 Cottage Park Ave
Cambridge, MA 02140 — North Cambridge
Based on HUD Small Area Fair Market Rent for Boston-Cambridge-Quincy, MA-NH HUD Metro FMR Area, a 5-bedroom in 02140 carries an estimated $4,830/mo in gross rent — about a 1.05% cap rate and $37,673/yr in estimated NOI at the $3,599,950 list price. Adjust every assumption in the calculator below.
Beds
5
Baths
4.5
SqFt
4,087
Style
Single Family
Built
2026
Striking new luxury single family on a quiet, tree-lined North Cambridge street, blending classic New England architecture with modern finishes and smart home readiness. Over 4,000 sf across four finished levels: 5 beds, 4.5 baths. The open first floor showcases a chef's kitchen with white oak shaker cabinetry, tile subway backsplash, quartz counters, Thermador stainless appliances, classic hood, and oversized island over herringbone oak floors. Half bath and full pantry with water dispensers rounds out the 1st floor. The second floor features a primary suite with spa bath, soaking tub and walk-in shower, plus a second en-suite bedroom and laundry room. Third floor offers two more bedrooms, full bath, and eave storage. Finished lower level features: entertainment room, private study, a bedroom and secondary laundry. Private fenced yard plus detached 1-car garage. Walk to Davis, Porter, Alewife T, Minuteman Bikeway, top schools, parks, and Cambridge/Somerville dining.
ADU Potential
Massachusetts allows one accessory dwelling unit by right in single-family zoning districts statewide (M.G.L. c. 40A §3; 760 CMR 71.00, effective Feb 2025). Estimated maximum ADU size for this property: 900 sq ft (the lesser of 900 sq ft or half the 4,087 sq ft principal dwelling). Lot size: 4,520 sq ft.
Based on listing data, which indicates the property type — not the zoning district. Local dimensional, septic (Title 5), and historic-district requirements still apply. Not legal advice — verify with the municipality.
Estimates — not financial advice
These figures are illustrative estimates for informational purposes only — not an appraisal, valuation, or guarantee of rent, income, or returns, and not financial, tax, or investment advice. Rent is either the figure reported on the MLS listing — in-place rent that may differ from market and is not verified against the actual leases — or, where the listing reports none, an estimate from HUD Small Area Fair Market Rents, a government benchmark that may differ from actual market rent. Each figure is labelled with its source. Cap rate, NOI, and returns depend on the assumptions shown, which you can change. MLS and other third-party data may be inaccurate or out of date. Verify all figures independently and consult your own financial, tax, and legal advisors before making any investment decision.
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Property Details
Financials
Parking
Interior Specifications
Climate & Utilities
Building & Exterior
Property & Lot
Amenities & Appliances
Electric Water Heater • Water Heater • Range • Dishwasher • Disposal • Microwave • Refrigerator • Washer • Dryer
Geography
Floorplan Breakdown
Structural Layout
Living Room
Lvl FirstDining Room
Lvl FirstKitchen
Lvl FirstFamily Room
Lvl BasementPrimary Bedroom
Lvl SecondBedroom 2
Lvl SecondBedroom 3
Lvl ThirdBedroom 4
Lvl ThirdProperty History
$3,599,950
Sep 30, 2026
MLS® 73584464
$3,628,900
Jul 21, 2026
MLS® 73528101
$3,628,900
Jun 2, 2026
MLS® 73528101
Listing Agent: John Raposo
Listing Office: eXp Realty LLC
MLS® Number: 73584464








