228 13th Street (The Ainsley)

A 14,178-square-foot lot, irregular in shape, running back from 13th Street alongside the public school parcel at the Fourth Avenue corner. Five stories, fifty feet, in an R6B contextual district. PLUTO records 34,527 gross square feet — 30,544 residential and 3,983 non-residential — while the Department of Finance's current assessment record for the same lot carries 47,630 gross square feet. The two city records do not agree, and neither reconciles cleanly against the twenty enclosed parking spaces, which ordinarily fall outside zoning floor area but inside a gross-area count. A buyer relying on a square-footage figure for anything consequential should take it from the offering plan and the architect's certification, not from either city record.

The unit plan is legible from the numbering. Five homes on the ground floor, six apiece on the second, third and fourth, and five penthouses at the top — twenty-eight, running one- to three-bedroom. That is a comparatively narrow range, which tends to produce a tighter price-per-square-foot band than a building offering studios through four-bedrooms, and a more homogeneous ownership base.

The sponsor's published description frames the design as drawing on Park Slope's own architectural vocabulary rather than the glass-and-metal language of the Fourth Avenue towers, with masonry, balconies and planting on the street elevation. Interiors — wide-plank white oak, quartzite kitchens, stone baths — were designed by an outside studio rather than in-house.

Below grade and at the rear, the building does the work that distinguishes it: an enclosed parking level of twenty spaces, twenty-four storage rooms, and a landscaped courtyard with a dog run and a play structure that could only exist on a lot this deep in a district this low.

Twenty-eight owners fund a lobby, a fitness center, a children's playroom, a residents' lounge, a courtyard with a dog run, a roof terrace with grilling stations, an enclosed parking facility and twenty-four storage rooms. That is one of the highest amenity-to-unit ratios of any recent condominium in this part of Brooklyn, and it is also a small denominator carrying a large fixed program. There is no commercial unit in the building contributing to the general common charges. The operating budget is the document that decides whether this building is a bargain or an obligation, and it should be read before anything else.

Because no offering plan or audited financial statement is on file with us, the capital questions are open. Put them to the managing agent directly and in writing: the current budget and the actual common charges against the projected first-year budget; the reserve balance and whether a reserve study has been performed; any assessment since the first closings in November 2025; how the parking level is operated, maintained and charged — whether parking owners pay a separate common-charge pool, as is typical, and what the ventilation, fire-protection and door-equipment maintenance obligations are; and the construction warranty position on a building barely a year into occupancy.

Then ask about the certificate of occupancy in specific terms. What conditions remain outstanding, what the sign-off schedule is, and whether any lender has raised it. A temporary certificate that is being routinely renewed while punch-list items close is an ordinary condition of a new building; one that has been renewed for years without converging is not. The record here shows an initial certificate in July 2025 and renewals in August and October 2025, January 2026 and April 2026 — a normal cadence so far, and worth confirming rather than assuming.

One records note, because it will surface: the Department of Buildings filed this project, and issued its certificates, under the building-identification number of the church that used to stand here (3023392), while the city's address and property records assign the new building its own number (3430345). Both refer to this building. A search on one will not return the other.

The lot carries no environmental designation. No E-designation appears on this lot, on this block, or on the block to the south in the Department of City Planning register — in contrast to the Fourth Avenue corners eleven blocks north, several of which carry hazardous-materials designations from the 2003 rezoning. We hold no Phase I or Phase II environmental report for this site, because we hold no offering plan for it. An offering plan would ordinarily disclose any such investigation, and a buyer who wants that record should request it from the sponsor. The absence of a city designation is a real and favorable data point; it is not an affirmative clean bill, and this page will not present it as one.

The Gowanus Canal is not this building's issue. The Environmental Protection Agency added the canal to the Superfund National Priorities List on March 2, 2010, and the cleanup is an active construction condition in the blocks along the water. This address is roughly a mile from the head of the canal, on the far side of Fourth Avenue, outside the rezoning area and outside the special district. The proximity arguments that apply to the buildings north of here — both the disruption and the eventual waterfront — largely do not apply to this one.

What does apply is R6B. Two things follow from a contextual row-house district. The first is protective: the block will not be rebuilt at scale, and the light and air a fourth-floor or penthouse buyer pays for here have a much better claim to permanence than the same views three blocks into the Gowanus rezoning area. The second is the reason to check the numbers: a built floor-area ratio of 2.44 against a 2.00 maximum is not, on its face, self-explanatory. The likeliest reconciliation is the treatment of enclosed accessory parking, which zoning generally excludes from floor area and PLUTO's gross-area figure does not — and a zoning-lot document, a certification and a declaration were all recorded on the site in June 2023. Ask the sponsor's counsel to walk the zoning analysis and the certificate conditions before contract.

Ownership form: Condominium, fee ownership. No ground lease or leasehold appears in the recorded documents.

Parking and storage are deeded property. Twenty parking lots and twenty-four storage lots, each with its own tax lot and its own class-four assessment. They are transferable, mortgageable and taxable in their own right — a materially different proposition from the licensed storage sold at some nearby buildings. Confirm at offer stage which spaces remain available, whether any are restricted to building occupants under the Zoning Resolution, and how the parking common-charge pool is structured.

Real estate taxes — no exemption. No 421-a, 485-x or other exemption appears on any of the 72 unit lots in Department of Finance exemption detail through the 2026/27 roll. The building's construction ran through the gap between the expiry of the old 421-a and the arrival of 485-x, and the site's previous religious exemption ended with the 2022 sale. There is a second-order point here that matters more than usual on a brand-new building: the city has only recently begun assessing this property as completed residential condominium, and first-year figures on a new building are frequently revised upward as construction value is added. Underwrite the actual current bill on the specific unit, and expect it to move.

Everything else is undocumented and should be confirmed in writing. We hold no offering plan, by-laws, house rules or financial statements. The right of first refusal, board approval, pet policy, leasing and sublet rules, minimum lease term, pied-à-terre position, flip tax and working capital contribution are not established here and should not be assumed from general Brooklyn condominium practice. Request the plan and the most recent financial statement from the managing agent and read the policy stack from the documents.

Recent sales

Recent closings at this building, curated by The Roebling Team research desk. 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) cleared a median $1,719/sf across 3 sales. Median listing discount -3.1% over ask.

Sales sourced from NYC Department of Finance recorded transfers (BBL 3-01034-7503) and verified listing data. Apartment-level facts (line, condition, asking-price context) curated and cross-verified by The Roebling Team research desk. 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.

Buy the parking space if you want one, and buy it as property. Twenty deeded spaces, twenty-eight apartments. Confirm availability, occupancy restrictions and the parking common-charge structure before you assume the arithmetic.

The certificate of occupancy is temporary. Initial July 2025, renewed four times, most recently April 2026. Ask what remains outstanding and when final sign-off is expected.

There is no tax abatement, and the assessment is young. Underwrite the current bill, then stress it — new condominiums are commonly reassessed upward in their first years as construction value is added.

Get the offering plan. It is the only document that settles the right of first refusal, the pet and sublet rules, the flip tax and the working capital contribution, and it is not on file with us.

Do not trust the square footage in the city records. PLUTO and the Department of Finance disagree by more than thirteen thousand square feet on this building. Take area from the plan and the architect's certification.

Twenty-eight owners, ten thousand square feet of amenities, no commercial income. Read the budget and the reserve position closely.

Two nearby addresses are not this building. 269–271 14th Street is a thirteen-residence condominium on block 1035 — a different block, a different building, a different condominium, completed in 2019. And every Department of Buildings filing and certificate for this property sits under the church's old building-identification number.

Lead with the parking. It is the rarest thing in the building and the one feature no competing new condominium in the Slope can match at this ratio. Sell it as deeded property, not as an amenity.

Sell R6B as permanence. Buyers looking at Fourth Avenue and Gowanus are buying into an eighty-two-block rezoning with a great deal left to build. This block is not in it. Light, air and scale here have a claim to durability, and that argument is worth making explicitly.

Have the certificate-of-occupancy status in the setup, not in the objection. A current status and an expected sign-off date removes the question. Silence invites it.

Explain the taxes as a feature. A full, permanent, knowable bill with no cliff in the 2030s is an easier thing to finance and to resell than an abatement approaching its step-down.

Assemble the document package. Offering plan, current budget, most recent financial statement, reserve position, parking and storage terms. In a building this new with no plan in general circulation, that package is the deal.

If you're considering 228 13th Street, also evaluate:

• 350 Butler Street — Passive House condominium in the Gowanus special district; the other new unabated building in this cluster, and the sharpest contrast on zoning context
• 251 1st Street — terraced Fourth Avenue condominium with an active 421-a; the abated, higher-rise alternative
• 205 12th Street — South Slope condominium one block north; the closest peer by street and scale
• 420 12th Street (Ansonia Court) — courtyard conversion nearby; the adaptive-reuse alternative with shared outdoor space
• 229 9th Street (Luna) — ground-up condominium on the far side of the canal; useful for how Gowanus-adjacent new construction prices
• 251 7th Street (The Argyle) — prewar Park Slope alternative on a comparable mid-block street
• 445 5th Avenue (The Slope on Fifth) — Fifth Avenue condominium; the retail-corridor comparison
• 500 4 Avenue — Fourth Avenue condominium nearby; the avenue-frontage alternative
• 575 Fourth Avenue — larger Fourth Avenue building with a deeper amenity program
• 480 Degraw Street — low-rise Gowanus-edge condominium with parking; the closest comparison on the parking question, though its spaces are licensed rather than deeded