279 Prospect Avenue

The building rises five stories on a 9,005-square-foot lot, with about 25,000 square feet of floor area per PLUTO. Every floor carries four apartments. On the Department of Finance roll, the B and C lines on floors two through five run about 1,360 square feet and the A and D lines about 940. The first floor differs: 1A is about 655 square feet, 1B and 1C about 1,280 to 1,320, and 1D about 915. The roll's figures are the city's gross measurements, not the sponsor's; measure before relying on them.

Parking spaces are 153 square feet each on the roll, and storage units range from about 30 to 110 square feet. Both are separate deeded condominium units with their own tax lots and their own share of the 421-a. Several apartment owners hold a space and a storage unit alongside their apartment, but the three are conveyed separately. A buyer gets only what the deed names.

The DOB filing records the building at about 58 feet. It was permitted under the R6 zoning in force before 2005. The same block now includes a 147-unit, five-story building completed in 2024 at 263 Prospect Avenue, per PLUTO. That building is a rental and is not part of this condominium.

The 421-a schedule, read directly from the Department of Finance record. On the 2025/26 roll, each apartment's exempt value equals 80 percent of its assessed value above a fixed pre-construction base. On the 2026/27 roll it equals 60 percent. That matches the statute's 25-year schedule: 21 years at 100 percent, then four annual steps of 20 points. The benefit began in 2004/05, so 2027/28 is at 40 percent, 2028/29 is at 20 percent, and full taxes apply from the 2029/30 tax year, starting July 1, 2029. Have the buyer's attorney confirm it against the unit's exemption detail.

No regulatory agreement found. ACRIS indexes no regulatory agreement or declaration of restrictions against the base lot or the unit lots, and the reviewed deeds show transfers to separately named buyers. Those names alone do not establish independence from the sponsor. Ask condominium counsel what eligibility the 25-year term rests on.

Finances and capital. No budget, audited statements or reserve figures are on file. At 22 years old the building is at the age when roofs, elevators and heating and cooling equipment come up for replacement. Ask for the last two years of audited statements, the reserve balance, any assessment history and the elevator maintenance contract. At five stories it sits below the six-story threshold of the city's façade-inspection program (Local Law 11).

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.

Market read. Most recent trades (2026 to date) cleared a median $928/sf (floor-adjusted) across 1 sale. Floor-adjusted means each sale is restated to a constant mix of floors, so the figure can differ from the plain median of the sales listed above. Median listing discount 1.5% from the last ask — a recurring negotiation gap worth pricing into any offer or listing strategy.

Sales sourced from NYC Department of Finance recorded transfers (BBL 3-01053-7501; 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.

Underwrite the 2029/30 tax bill. The exemption is at 60 percent for 2026/27 and gone by July 2029. Use the full-tax number for any hold longer than three years.

Confirm what conveys. Parking and storage are separate units. If the listing includes them, the contract and the deed must name the lot numbers.

Ask for documents early. Apart from the recorded declaration and by-laws, nothing about this building's governance or finances is in the public record. Budget, reserves, leasing rules and pet policy all have to come from the managing agent.

Price with the tax schedule in view. Buyers' attorneys will see the phase-out. Present the year-by-year tax figures up front so buyers can evaluate the phase-out before negotiating; that does not guarantee the outcome of diligence.

Sell the parking and storage deliberately. Decide early whether to bundle them or sell them separately. Other owners in the building are the most likely buyers of a separate space.

Lead with the building's scale. Twenty apartments, two elevators and deeded parking belong in the first lines of the listing.

If you're considering 279 Prospect Avenue, also evaluate:

• 162 16th Street (The Vue) — the ten-story condominium on the next block west, from the same architect of record, with a 25-year 421-a that runs to 2033/34
• 372 15th Street (The Park Pavilion) — a 30-residence condominium of the same generation and architect of record whose 15-year 421-a has fully expired
• 675 Sackett Street — a same-generation Park Slope condominium whose 25-year 421-a runs one year behind this one
• 155 15th Street (Harbor Hill) — a 21-residence South Slope condominium with a garage, in the final year of a 15-year 421-a
• 939 Union Street — a 2003–04 Park Slope condominium whose 15-year 421-a has expired
• 575 Fourth Avenue — a 70-residence 2018 condominium near the same R station
• 343 Fourth Avenue — a larger 2006 Fourth Avenue condominium with a garage
• 1638 Eighth Avenue — a 27-residence condominium with parking at the south end of the Slope