443 12th Street (Ansonia Storage Warehouse)
443 12th Street, Brooklyn, NY 11215
BBL 3010960050 · BIN 3026297
- Year built
- 1909
- Type
- Cooperative
- Units
- 36
- Floors
- 5
- Landmark
- Designated
- Pets
- Up to four pets per apartment without prior approval, no more than two dogs and three cats. Dogs expected to exceed 50 pounds need board approval, per the house rules on file
- Financing
- Listing records show a 20% minimum down payment. Not documented in the board documents on file; confirm with the managing agent
Own an apartment here? See what it would sell for.
A Private Pricing Opinion — what your apartment at Ansonia Storage Warehouse, the name under which the Landmarks Preservation Commission records the building. Market records also use "Ansonia Warehouse" and, wrongly, "Ansonia Clock Factory." The clock factory is the complex across the street 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.
The Ansonia Clock Company moved to Park Slope in 1879 and filled the block between 12th and 13th Streets with what was then described as the largest clock factory in the world. In 1909 it built a storage warehouse across 12th Street: five stories of brick by Parish & Schroeder, raised between April and November of that year. 443 12th Street is that building. The factory complex across the street — now 420 12th Street (Ansonia Court) and 444 12th Street (Ansonia Muse) — is the famous one. This is the outbuilding, and it had the more direct path to housing.
The building stayed in storage use for seventy years, and when the conversion sponsor bought it in June 1979 its most recent use had been storing voting machines. The sponsor filed conversion plans that year and DOB approved them in December 1979. The offering plan went out in March 1981 describing a vacant loft building with no tenants in possession. The plan proposed 36 open loft apartments with raised sleeping platforms behind rail-height partitions, under Article 7-B of the Multiple Dwelling Law. That law is how New York legally converted commercial buildings to residential use. The corporation took title in April 1982.
The timing matters. The Loft Law, which legalized buildings where people were already living illegally, was enacted in June 1982, two months after this building closed as a cooperative. 443 12th Street was never part of that system. It was a vacant-building conversion with a residential certificate of occupancy, apartments sold to new buyers, and a clean legal footing. That is a better starting point than many of Brooklyn's industrial conversions of the same years.
The corporation's name is a small historical oddity. It was organized in 1980 as 443-47 12th Street Housing Corporation and took the warehouse's own name, Ansonia Storage Warehouse, before closing. As a result the co-op corporation carries the name of the commercial building it replaced. That confuses searches, lender questionnaires and title reports, and a buyer's attorney should expect it.
Architecture and unit composition
The building is load-bearing brick, five stories over a full cellar, in the Romanesque Revival manner the LPC assigns. It was built for heavy storage, which shows in the generous heights: 11 feet 6 inches floor to floor above the ground floor and 14 feet at the ground floor, per the conversion architect's report. Listing records describe beamed ceilings of about 11 feet, large windows, exposed brick and hardwood floors. Those are the features buyers come for.
The offering plan fixed the layout that still defines the building. There are eight duplexes on the basement and first floor, with double-height space and — in the original plan — kitchens on the lower level, and seven apartments on each of floors two through five. Most apartments were laid out as open lofts with no enclosed rooms other than bathrooms. Forty years of renovation have turned many of them into conventional bedroom layouts, and the plan itself warns that apartments may have been altered from the typical floor plan. Inspect each apartment, and treat any bedroom count as current condition rather than original design.
The roof is the other asset. It is common space with grills and planters maintained by a shareholder gardening committee. Two top-floor apartments, 5B and 5E, have exclusive rights to defined portions of the roof under the original offering plan, reached through restored scuttle hatches. The house rules say plainly that dormers and skylights belong to the corporation, and that shareholders with structures next to their apartments have no rights to the surrounding roof.
Building operations
This is a small, hands-on cooperative. It has a professional managing agent but no resident superintendent — the house rules say so and ask shareholders to share cleaning, snow and trash duties. Move-ins and renovations follow detailed written rules. Renovations fall into four categories with monthly fees and deposits. Every exterior change — windows, dormers, anything visible from 12th Street — requires Landmarks approval on top of the board's.
The capital record is that of a masonry building more than a century old. DOB filings show a burner and gas conversion in 2003, a boiler replacement in 2008, stucco on the east wall in 2010, and façade and roof repairs filed in 2017. Board communications on file from 2021 refer to a recently completed elevator upgrade. They also record water getting into the rear lower-level apartments and the boiler room during the 2021 remnants of Hurricanes Henri and Ida, followed by waterproofing of the lower rear wall and plans for sump pumps in the basement and elevator pit. Dormer, skylight and upper-façade sealing were identified as phased projects. At five stories the building sits below the six-story threshold of the city's façade-inspection program (FISP/Local Law 11).
Underlying mortgage and reserves. The corporation's current mortgage dates from May 30, 2017, when the existing loan was consolidated with Astoria Bank under a recorded $1,660,000 agreement. Per the 2021 shareholder tax letter on file, outstanding principal was about $655 per share at December 31, 2021 — roughly $1.3 million across the plan's 2,000 shares — and was paying down by about $95,000 a year. The maturity date is not in the documents we reviewed. Board communications from 2021 show a savings reserve in the mid-five figures, held alongside operating funds and a bank line of credit. That is modest for a masonry building of this age. Get the current audited financial statements, the mortgage maturity and the reserve balance before pricing an apartment here.
Policy framework
Board approval: All sales require the board's prior written approval. The package includes two years of tax returns, employment and personal references, the mortgage commitment, recent pay stubs, asset statements, a credit report and the contract of sale. An interview is scheduled no sooner than two weeks after the package is complete, and the decision is delivered in writing. All maintenance, assessments and late charges must be current before the board approves a sale, sublet or refinance.
Subletting: Board approval required. The shareholder must have lived in the building for 12 consecutive months. Sublets are limited to 24 months on the board's form, no more than two apartments may be sublet at once, requests are handled first come, first served, and a $1,500 fee applies.
Pets: Up to four without prior approval, no more than two dogs and three cats. Dogs expected to exceed 50 pounds need board approval.
Use: No commercial use. The house rules define that as delivering goods or services to clients on site, or receiving clients regularly.
Proprietary lease: The term was extended to September 30, 2069 by shareholder vote on November 16, 1998.
Transfer fee: Collected on sales per board communications on file. Confirm the formula with the managing agent.
Financing, pied-à-terre, LLC and trust ownership, gifting, co-purchasing: Not addressed in the documents on file. These must come from the managing agent.
Recent sales
443 12th Street trades as landmarked loft co-op product in a district of brownstones. It is priced per room like the rest of the Park Slope co-op market, but buyers are paying for ceiling height, window size and open plan. The within-building spread is wide. The basement/first-floor duplexes, the fifth-floor apartments — especially the two with exclusive roof areas — and fully renovated lofts set the top of the range. Apartments that keep the original raised-platform layout are priced as projects, because turning a sleeping loft into an enclosed bedroom is a major renovation that needs board approval.
The co-op structure sets the buyer pool: a board package, an interview, sublets limited to two apartments at a time, and financing subject to board approval. That favors owner-occupants and narrows the investor market. The real comparison set combines Brooklyn's other converted-industrial co-ops, the loft condominiums across the street and the Park Slope prewar co-op market, adjusted for the step down from condominium flexibility. Unit-level transaction history is maintained in The Roebling Research Library and shared with clients during diligence.
The retrade record
Lines that have traded more than once in the public record — the building’s appreciation arc, apartment by apartment.
Recent transfers at this building, sourced from NYC Department of Finance records. Apartment-level detail (line, condition, asking-price context) verified upon consultation request.
| Date | Unit | Price |
|---|---|---|
| Jul 29, 2026 | 1H | $1,815,000 |
| Jul 13, 2026 | 5F | $1,250,000 |
| Aug 27, 2025 | 2F | $1,025,000 |
| Mar 25, 2025 | 3A | $507,000 |
| Nov 12, 2024 | 1E | $787,500 |
| Apr 27, 2023 | 3C | $1,075,000 |
Sales sourced from NYC Department of Finance recorded transfers (BBL 3-01096-0050) 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.
At the recent median sale of $1.02M (5 transfers since 2024), a buyer putting 25% down would pay about $22,644 to close, or 2.2% of the price.
- Mansion tax: $10,250
- No mortgage recording tax or title insurance on a co-op purchase
- Attorneys, lender, building fees and filings: $12,394
Assumes a resale (the seller pays transfer taxes), a $4,500 attorney fee and a mortgage on the rest.
Keep up with Ansonia Storage Warehouse, the name under which the Landmarks Preservation Commission records the building. Market records also use "Ansonia Warehouse" and, wrongly, "Ansonia Clock Factory." The clock factory is the complex across the street and its market
The Roebling Report, monthly: Manhattan sales data and analysis, including buildings likeAnsonia Storage Warehouse, the name under which the Landmarks Preservation Commission records the building. Market records also use "Ansonia Warehouse" and, wrongly, "Ansonia Clock Factory." The clock factory is the complex across the street. 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
Get the financial statements and the mortgage terms. The underlying loan dates from 2017 and was paying down by about $95,000 a year in 2021. Find out when it matures and what a refinancing would do to maintenance. A small reserve in a building this old deserves a direct question about planned assessments.
Ask about water. The rear lower-level apartments took water in the 2021 storms. If you are looking at a basement/first-floor duplex, ask what was repaired, whether the sump pumps were installed, and how the apartment fared in later storms.
Know what the lease permits you to change. Enclosing a sleeping loft, moving a kitchen or replacing windows falls in the house rules' higher renovation categories, and any exterior change needs Landmarks approval. Price the renovation you want only after confirming it can be approved.
Plan for the sublet cap. No more than two apartments may be sublet at once, only after 12 months of residence and for no more than 24 months. If you might need to rent the apartment out, this building is a poor fit.
Expect the name confusion. The corporation is Ansonia Storage Warehouse Corp., formerly 443-47 12th Street Housing Corporation, and the lot is indexed at 445 12th Street. Your lender and title company will ask.
What to know if you’re selling
Tell the true history in two sentences. A 1909 Ansonia Clock Company warehouse by Parish & Schroeder, converted to lofts in 1981–82 with a residential certificate of occupancy. Do not call it the clock factory — that is across the street, and informed buyers know the difference.
Correct the 1960 date. The Department of Finance year is wrong, and buyers will find it. The offering plan and the LPC both date the building 1909.
Have the board package ready early. A complete package moves faster here, because no interview is scheduled until everything is in. Get the transfer fee figure and the managing agent's financial summary in hand before you set the price.
Lead with the volume and the roof. Eleven-foot beamed ceilings, big windows and a shared roof deck with long views are what no brownstone floor-through on the block can offer. If your apartment is 5B or 5E, the exclusive roof area is the headline.
Comparable buildings
If you're considering 443 12th Street, also evaluate:
- 420 12th Street (Ansonia Court), the Ansonia Clock Company factory across the street, converted to a 70-unit cooperative in 1982; the same history at twice the scale
- 444 12th Street (Ansonia Muse), the c.1881 Ansonia factory building across the street, converted to a loft condominium in 2001–02; the condominium alternative on the same block
- 28 Old Fulton Street (The Eagle Warehouse), an 1890s Brooklyn warehouse converted to a cooperative; the borough's best-known peer in the format
- 8 Old Fulton Street (Brooklyn City Railroad Company Building), an 1860–61 commercial building in Fulton Ferry, now a cooperative
- 423 Atlantic Avenue (The Ex-Lax Building), an industrial conversion in Boerum Hill; the same loft buyer in a different neighborhood
- 145 Park Place (Park Place Condominiums), a Park Slope conversion of a non-residential building to condominium
- 230 Park Place, a 1937 Prospect Heights co-op; the conventional prewar co-op alternative for the same buyer
More Park Slope buildings
- 40 Prospect Park West — 1942 co-op
- 412 & 420 Eighth Avenue, 412 and 420 Eighth Avenue — 1920 condominium
- 420 12th Street (Ansonia Court) — 1880 co-op
- 444 12th Street (Ansonia Muse) — 1881 condominium
- 445 5th Avenue (The Slope on Fifth), 445 Fifth Avenue — 2025 condominium
- 459 12th Street — 1916 co-op
The neighborhood
For the full neighborhood — its buildings, character, and market — read The Roebling Team Guide to Park Slope.
The full playbook — what goes in the package, how boards read your financials, the interview, and the timeline — plus sample cover, reference, and personal letters you can adapt.
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 Ansonia Storage Warehouse, the name under which the Landmarks Preservation Commission records the building. Market records also use "Ansonia Warehouse" and, wrongly, "Ansonia Clock Factory." The clock factory is the complex across the street?
Request a private building brief with the relevant comparable sales, current and off-market availability, and an apartment-specific view of value.