- Year built
- 1884
- Type
- Condominium
- Landmark status
- Not an individual landmark; in the Park Slope Historic District Extension II
- NYC Landmarks Preservation Commission records, updated February 2026
Every recorded sale at this building, 2021–2025
Price-per-square-foot over time, the line- and floor-premium curves, and every recorded sale.
- Median $/sf, 2025
- $1,165
- 1 sale
- Listing discount
- 2.0%
- Recorded sales
- 7
- On record
- 2021–2025
Own an apartment here? See what it would sell for.
A Private Pricing Opinion — what your apartment at 84 Sixth Avenue would likely sell for today, what it costs to sell, and what you’d walk away with — reviewed personally against condition, exposures, renovation quality, and the competition actually on the market.
About the building
84 Sixth Avenue was designed and built by John P. Seeley in 1884. Its Neo-Grec brownstone frontage includes an angled bay, incised ornament around the openings, a projecting entrance hood and a bracketed cornice. The house became part of the Park Slope Historic District Extension II in 2016. A later renovation created four condominiums, with the Attorney General accepting the sponsor's filing in August 2022 and the first apartment closings following in 2023.
The conversion places a garden duplex at the base and floor-through homes above, with balconies and roof outdoor space among the upper configurations. Central air conditioning, in-unit laundry and storage support the modern interiors. The lower home extends across two levels, while the upper homes retain the width and front-to-back orientation of the townhouse. The preserved bay projects toward Sixth Avenue and brings angled light into the rooms behind it.
Local Law 97
This building is below the 25,000 sq ft threshold at which LL97 limits apply to a building on its own. It is still covered if it shares a tax lot or condominium board with buildings totaling over 50,000 sq ft; confirm on DOB’s covered-buildings list.
See full Local Law 97 analysis →Recent sales
Recent closings at this building, from The Roebling Research Library. Prices are the transfer amounts recorded with the NYC Department of Finance; apartment-level detail is checked against the building’s own file in The Roebling Research Library before publishing.
| Date | Unit | Apartment | Price | PPSF | vs. Ask |
|---|---|---|---|---|---|
| Oct 30, 2025 | 1 | 2 BR · 2.5 BA · 1,695 sf | $1,975,000 | $1,165/sf | -1.0% |
| Dec 18, 2024 | 1 | 2 BR · 2.5 BA · 1,695 sf | $2,025,000 | $1,195/sf | -5.8% |
| Aug 1, 2023 | 2 | 2 BR · 2 BA · 1,139 sf | $1,795,000 | $1,576/sf | +0.0% |
| Jul 17, 2023 | 3 | 3 BR · 2 BA · 1,168 sf | $1,865,000 | $1,597/sf | -1.6% |
| Jun 29, 2023 | 1 | 2 BR · 2 BA · 1,695 sf | $2,250,000 | $1,327/sf | -2.0% |
| May 13, 2021 | — | 5 BR · 5 BA · 3,980 sf | $3,100,000 | $779/sf | -17.3% |
Market read. Most recent trades (2025) cleared a median $1,165/sf (recorded) across 1 sale. Median listing discount 2.0% from the last ask — a recurring negotiation gap worth pricing into any offer or listing strategy.
The retrade record
Lines that have traded more than once in the public record — the building’s appreciation arc, apartment by apartment.
Full closing history with price-per-square-foot over time, the complete retrade record, and every line that has traded.
Sales sourced from NYC Department of Finance recorded transfers (BBL 3-00935-7504; each condominium apartment is its own tax lot). Apartment-level facts (line, condition, asking-price context) curated and cross-verified in The Roebling Research Library. Not all transactions cross-verify with ACRIS records — sponsor and LLC purchases sometimes record at stipulated values rather than market price; square footage from recorded condo declarations and offering plans.
What would your apartment rent for?
Enter your apartment and I'll send you what it would rent for, from comparable closed leases at 84 Sixth Avenue and nearby.
Buying here? Condo closing costs with a mortgage typically run 3 to 6% of the price. See NYC co-op and condo closing costs, line by line.
Keep up with 84 Sixth Avenue and its market
The Roebling Report, monthly: Manhattan sales data and analysis, including buildings like 84 Sixth Avenue. Unsubscribe anytime.
We’ll use your email for The Roebling Report and note your interest in this building. See our privacy policy.
What to know if you’re buying
Four owners maintain a protected brownstone. Repairs to the projecting bay, cornice and other designated exterior features can involve LPC review and specialized masonry work. Those costs fall within a small association, making the division of common exterior obligations and private balcony or roof-area obligations consequential for each owner.
Comparable buildings
- 220 Park Place — another small condominium in a prewar residential building.
- 153 Lincoln Place — a historic condominium with a larger association and similar neighborhood architecture.
- 64 Seventh Avenue — a prewar condominium offering a larger avenue-building comparison.
- 497 Pacific Street — a low-rise prewar condominium with more apartments sharing expenses.
More Park Slope buildings
- 8 Windsor Place — 1920 condominium
- 808 Eighth Avenue — 1904 co-op
- 82 Sterling Place — 1882 condominium
- 851 Carroll Street — 1894 condominium
- 853 Carroll Street — 1920 condominium
- 86 Prospect Park West — 1908 co-op
The neighborhood
For the full neighborhood — its buildings, character, and market — read The Roebling Team Guide to Park Slope.
How to read the facts on this page. Items attributed to an offering plan describe the building as it was offered at that filing — unit mix, square footage, the amenity program as planned. They are not a statement about how the building operates today. Tax and compliance figures are sourced separately to current City records and carry their own dates. House rules, staffing and fee policy can change by board resolution without any public filing: treat every policy line here as a starting point for diligence and confirm it with the managing agent. Where this page compares one building or neighborhood to another, that is our analysis of the recorded record — it names the measure, the period and the sample it rests on, and it is an observation about medians rather than a prediction about any particular apartment.
Considering a move at 84 Sixth Avenue?
Request a private building brief with the relevant comparable sales, current and off-market availability, and an apartment-specific view of value.
646.939.7375 · c.cohen@compass.com