91 Old Harbor Street
South Boston, Boston · 91 Old Harbor St
91 Old Harbor Street in South Boston, Boston has 5 recorded condominium sales dating back to 2017, a median sale price of $920K and an average of $695 per square foot. Every figure below is drawn from recorded deeds — not listings, not estimates.
91 Old Harbor Street is one of 1,024 condo buildings CURVE covers in South Boston, where the median recorded price is $511 per square foot. By that measure it ranks #185 of 1024 in the neighborhood.
The record
Sales activity
Recorded sales by year
Every deed recorded in 91 Old Harbor Street, by year, with that year's median price.
Sales by price point
How 5 recorded sales distribute across the price ladder.
Unit mix sold
Bedroom count across recorded sales.
5 most recent sales
| Unit | Date | Beds | Type | Price | $/SF | Change |
|---|---|---|---|---|---|---|
| 3 | 8/15/2025 | 3 Beds | Resale 1 | $1.1M | $874 | +25% |
| 2 | 5/18/2021 | 3 Beds | Resale 1 | $940K | $733 | +12% |
| 2 | 6/20/2017 | 3 Beds | Developer Sale | $839K | $654 | — |
| 3 | 5/25/2017 | 3 Beds | Developer Sale | $899K | $701 | — |
| 1 | 5/5/2017 | 3 Beds | Developer Sale | $920K | $511 | — |
The full 91 Old Harbor 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 91 Old Harbor Street?
5 recorded sales, going back to 2017, of which 2 are resales. This page shows the 5 most recent; members see all of them.
What has 91 Old Harbor Street done over time?
Resales in the building have changed hands at an average of +18.3% against their prior recorded price, after an average hold of 6.1 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.