1 Prospect Park West

Nine stories of brick, limestone and terra cotta on an irregular 18,500-square-foot lot, with 171 feet of frontage on Prospect Park West — the widest residential façade on the avenue. Total building area is about 133,400 square feet, split between roughly 120,200 square feet of residential space and about 13,200 square feet of ground-floor commercial. The built floor-area ratio of roughly 7.2 exceeds the 6.02 that R8X zoning would permit for residential use today, which is a direct benefit of converting an existing envelope rather than building new.

The residential count sits at 64 units per the Department of Finance, with one commercial unit alongside; sixty-five condominium unit lots are recorded on the tax map, and the developer's 2017 pre-offering filing described 66 residences. The spread is normal for a conversion where unit lines were combined or reconfigured during construction, but it is exactly the kind of detail an attorney should reconcile against the recorded declaration, because the unit's common interest — not its marketing description — drives its share of common charges and its vote.

Because the building is a converted institutional block rather than a purpose-built apartment house, the plate is deep and the unit plans are irregular. Exposure quality varies more than floor number does: the plaza and park frontage is the premium, north-facing upper floors pick up the Manhattan skyline, and the rear of the plate looks into the block. Ceiling heights and window proportions likewise vary with what the 1925 structure gave the architects on each floor. See the specific apartment; a floor plan will not tell you what the light is like.

The condominium is young. The offering plan is dated February 12, 2019, sponsor closings began in December 2021, so the operating record a buyer can examine is short; confirm whether and when the sponsor turned over board control. Ask for the first full-year operating budget against actual results, the reserve balance, the status of any sponsor punch-list obligations, and whether the sponsor retains any unsold units or the commercial condominium.

Three items deserve specific attention in a building of this type. First, the ground-floor commercial space: roughly 13,200 square feet of retail is a meaningful potential offset to residential common charges if it is leased and if its income runs to the residential section — establish how the declaration allocates it, who owns it, and what it currently produces. Second, the amenity load: a fitness studio, a movement studio, spa facilities, a playroom, a gallery and a landscaped roof terrace with an orchard are staff- and maintenance-intensive relative to 64 units, and amenity cost per unit in a small building is structurally higher than in a large one. Third, the envelope: converting a 1925 masonry institutional building produces a hybrid of original façade and new systems, and the first FISP/Local Law 11 cycle under condominium ownership is the one that establishes what the masonry actually needs.

No property tax abatement or exemption is documented in the records reviewed. Do not assume one exists; pull the current bill for the specific unit and run the carrying cost against it.

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 $1,704/sf (floor-adjusted) across 5 sales. 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 0.0% from the last ask.

Sales sourced from NYC Department of Finance recorded transfers (BBL 3-01066-7504; 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.

You are buying the address and the ownership form. Grand Army Plaza frontage with condominium flexibility is close to unavailable otherwise in this part of Park Slope. That is the pricing argument and it should be tested against actual comparable sales, not assumed.

Reconcile the unit count and the common interest. 64 residential units per the Department of Finance, 65 unit lots on the tax map, 66 in the developer's pre-offering filing. Your attorney should confirm the unit's designation, square footage and common interest against the recorded declaration.

Pull the tax bill. No abatement is documented. In a building with amenity-heavy common charges, the tax line is the variable that most often breaks a buyer's model.

Ask about the retail condominium. Roughly 13,200 square feet of ground-floor commercial space. Who owns it, how the declaration allocates its charges, and whether it is leased are all questions with direct consequences for residential common charges.

Underwrite the amenities against 64 units. A fitness studio, movement studio, spa, playroom, gallery and orchard roof terrace are wonderful and they are not free. Ask for the amenity line in the operating budget.

Confirm the house rules yourself. Pet policy, sublet minimum term, in-unit washer/dryer and move-in procedures were not documented in the materials reviewed for this page. Get the current rules in writing before you sign.

Lead with the ownership form, not just the view. Most of the park-front competition within walking distance is cooperative, with board approval; the main condominium alternative is the new-construction 1 Grand Army Plaza. Condominium ownership at Grand Army Plaza is the scarce thing you are selling.

Sell the conversion, not the 1925 date. Buyers hear "1925" and price prewar systems risk. The mechanicals, elevators, windows and layouts are 2019–2021 work inside a 1920s shell — say that plainly and be ready to document it.

Comp against condominiums, in dollars per square foot. A per-room comparison against the surrounding co-ops will understate this building in every direction that matters.

Have the operating record ready. The condominium is young. A buyer's attorney will want the budget-to-actual, the reserve balance, the retail arrangement and the sponsor's remaining obligations. Assembling that package in advance is worth days on the closing calendar.

Address the building's history directly. The clubhouse, the nursing home and the 2014–2016 litigation are all easily found and all long resolved. A seller who states the chain of ownership plainly controls the story; a seller who does not, does not.

If you're considering 1 Prospect Park West, also evaluate:

• 1 Grand Army Plaza (Richard Meier on Prospect Park) — the other condominium on the plaza; new construction rather than conversion
• 35 Prospect Park West — Emery Roth's 1929 cooperative four blocks south; the park-front co-op alternative at much larger apartment scale
• 40 Prospect Park West — 1942 cooperative on the same avenue; the smaller, more restrictive co-op alternative
• 39 Plaza Street West — Rosario Candela's 1926 cooperative on the Plaza's western arc
• 550 Vanderbilt Avenue — the Prospect Heights condominium at Pacific Park; the closest full-amenity condo peer
• 700 Pacific Street — Prospect Heights condominium; newer construction, different price basis
• 445 5th Avenue — the Fifth Avenue condominium tower in Park Slope
• 343 4th Avenue — the 2006 Fourth Avenue condominium; the earlier Park Slope condo generation
• 10 Plaza Street East — the 1959 full-service co-op on the Plaza