421-423 Marlborough Street
Back Bay, Boston · 421-423 Marlborough St
421-423 Marlborough Street in Back Bay, Boston has 25 recorded condominium sales dating back to 1992, a median sale price of $319K and an average of $521 per square foot. Every figure below is drawn from recorded deeds — not listings, not estimates.
421-423 Marlborough Street is one of 430 condo buildings CURVE covers in Back Bay, where the median recorded price is $769 per square foot. By that measure it ranks #415 of 427 in the neighborhood.
The record
Sales activity
Recorded sales by year
Every deed recorded in 421-423 Marlborough Street, by year, with that year's median price.
Sales by price point
How 25 recorded sales distribute across the price ladder.
10 most recent sales
| Unit | Date | Beds | Type | Price | $/SF | Change |
|---|---|---|---|---|---|---|
| 421-4 | 11/24/2025 | — | Resale 3 | $660K | $971 | +49% |
| 423-1 | 12/7/2023 | — | Developer Sale | $880K | $1,016 | — |
| 421-12A | 12/15/2014 | — | Developer Sale | $893K | $1,879 | — |
| 421-3 | 3/14/2014 | — | Resale 2 | $500K | $693 | +15% |
| 421-8 | 7/17/2013 | — | Resale 4 | $489K | $709 | +31% |
| 421-9 | 3/20/2012 | — | Resale 1 | $457K | $633 | +9% |
| 421-4 | 5/16/2008 | — | Resale 2 | $443K | $651 | +4% |
| 421-3 | 9/29/2006 | — | Resale 1 | $435K | $602 | +36% |
| 421-11 | 11/1/2005 | — | Developer Sale | $500K | $704 | — |
| 421-4 | 5/5/2005 | — | Resale 1 | $425K | $625 | +41% |
The full 421-423 Marlborough Street record
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About this record
Where does this data come from?
Every sale shown is a deed recorded with the Boston registry — the legal record of the transaction, not a listing or an estimate. CURVE assembles, verifies and reconciles each one to the building and the unit.
How many sales are in 421-423 Marlborough Street?
25 recorded sales, going back to 1992, of which 12 are resales. This page shows the 10 most recent; members see all of them.
What has 421-423 Marlborough Street done over time?
Resales in the building have changed hands at an average of +28.2% against their prior recorded price, after an average hold of 5.5 years.
What do members see that I don't?
The complete sales table, each unit's full chain of title, buyer and seller names, financing detail, the deed book and page behind every figure, the condo documents, and reports you can send to a client.