444 12th Street (Ansonia Muse)
444 12th Street, Brooklyn, NY 11215
BBL 3010987510 · BIN 3347745
- Year built
- 1881
- Type
- Condominium
- Units
- 37
- Floors
- 7
- Landmark
- Designated
- Pets
- Permitted per management-sourced records
Every recorded sale at this building, 2004–2026
Price-per-square-foot over time, the line- and floor-premium curves, and every recorded sale.
- Median $/sf
- $1,605
- Listing discount
- 1.1%
- Recorded sales
- 64
- On record
- 2004–2026
The Ansonia Clock Company came to Park Slope in 1879, bought the entire block from Seventh Avenue and 12th Street through to Eighth Avenue and 13th Street, and put up what contemporaries described as the largest clock factory in the world. On October 27, 1880 it burned. The company rebuilt immediately and larger, to designs by Samuel Curtiss, Jr., and kept expanding across the block into the twentieth century. At its height roughly 1,300 people worked here, and the streets around the plant filled with their houses — which is a substantial part of why the surrounding blocks look the way they do. Manufacturing ended in 1929, when the machinery was sold and shipped out of the country.
444 12th Street is a survivor of that immediate post-fire rebuild. The LPC dates it c. 1881 from a construction notice in American Architect and Building News of April 16, 1881, and attributes it to Curtiss — the same architect and the same year as the larger building at 420 12th Street that became Ansonia Court. That dating is the single most important fact on this page, because the widely circulated 1920 date for this building is wrong, and it is wrong in a direction that costs the building its provenance. A 1920 warehouse is a building. An 1881 Ansonia factory is a piece of the neighborhood's founding industry, and it is priced and marketed differently.
The style the LPC assigns is American Round Arch, the American industrial reading of German Romanesque Revival: load-bearing brick, arch-headed window openings with brick lintels, decoration achieved with brickwork because brick was what a masonry builder had. Those openings were sized to push daylight deep into a manufacturing floor before electric light was cheap, and in a residential conversion they become the apartments' defining feature. Ceiling volume and window area, not room count, are what this building sells.
The conversion itself is the second half of the story and it is unusually well documented in the public record. ZR Ansonia LLC took title in December 1999, financed the work in October 2000, filed the condominium subdivision in May 2001, recorded the declaration on September 24, 2001, closed its first units that November, and received the residential certificate of occupancy on November 22, 2002. The work included a two-story brick-and-stucco rooftop addition — the reason the building reads as seven stories today when the LPC records it as five stories plus a two-story penthouse — plus metal balconies on the west elevation, first-floor decks, and the conversion of the historic courtyard into landscaped common space. The building came into the Park Slope Historic District Extension a decade later, in 2012, with those alterations already in place and recorded as such.
The structure a buyer most often misses is that this condominium is four buildings. Along with the c.1881 factory, the tax lot carries the two-story industrial building at 446 12th Street, a wall and structure at 423 13th Street, and the two-story former factory and garage at 431–433 13th Street, which was raised a story after 1988. They are one condominium, one budget and one façade obligation. That is where the 22 parking units and the 3,400 square feet of garage area live, and it is why the condominium's capital agenda is broader than a single loft building's.
Architecture and unit composition
Five stories of load-bearing brick from 1881 with a two-story addition above, on a 26,700-square-foot lot holding 61,453 square feet, arranged around a courtyard shared with the neighboring condominium at 438 12th Street. The building is entered from that courtyard on its west face rather than from the 12th Street sidewalk — a sequence inherited directly from the factory, which was walled from the street with a guard station at the gate. The historic perimeter wall and the guard-station structure both survive and are recorded by the LPC as contributing features.
The 37 residences are loft plates, and the mix is unusually varied because the plan is derived from an industrial grid rather than a residential one. Six of the 37 are duplexes stacked across two floors. Five are penthouses in the rooftop addition, which is where the outdoor space and the long views over the low South Slope roofscape are. Two carry loft designations rather than floor-and-line numbering. First-floor units have private fenced decks; upper west-facing units on floors three through five have metal balconies. There is no representative layout at this address, and any pricing exercise that treats one unit as a proxy for another will be wrong.
Three consequences follow from the fabric, and each belongs in a diligence file. Windows: the arch-headed openings are character-defining features inside a designated historic district, so sash replacement, repair and any change to configuration run through the Landmarks Preservation Commission on the Commission's timeline. Structure: a nineteenth-century mill floor carries and transmits sound differently from concrete, and a buyer sensitive to impact noise should visit at an active hour. Conditioning: tall volumes and large glazed areas cost more to heat and cool than the six-story brick norm in the district, and the condominium's fuel line reflects it.
Building operations
The condominium is professionally managed and runs with part-time doorman coverage rather than a 24-hour attended lobby, laundry in the building, an elevator, the shared courtyard, and the on-site garage. The garage is worth understanding structurally: it is not an amenity the condominium licenses out, but 22 individually deeded condominium units that trade separately from the residences. A residence and a parking space at this address are two conveyances, and a buyer who wants both should establish early whether a space is included, available, or in the market.
The capital agenda here is a mill building's, not an apartment house's. Large brick elevations across four structures, an 1881 roof line plus a 2001 rooftop addition, oversized landmarked windows, a landscaped courtyard with its own drainage and planting budget, and a garage — all carried by 37 residences. The recorded history shows the building working through exactly that: masonry repair filings in 2009 and 2012, sidewalk sheds in 2006, 2008 and 2013, pipe scaffolding in 2017, a lobby renovation in 2010, and boiler and domestic hot-water replacements in 2013 and 2015. The payoff is that the current façade cycle — cycle 9, filed January 17, 2024 — came in SAFE, after three consecutive cycles of SWARMP status and an initial UNSAFE filing in 2012.
That is a good trajectory, and it is also the reason listing records reference an ongoing capital assessment. Ask management for the current assessment amount and end date, the reserve balance, the last two FISP filings, the courtyard maintenance line, and the window program history with the Commission. Read them together, not separately.
Policy framework
Ownership form: Condominium. Transfers close through a right of first refusal rather than a board approval, on the shorter condominium timeline — a meaningful difference from Ansonia Court next door, which is a cooperative.
Pets: Permitted per management-sourced records. Confirm limits in the house rules.
Subletting, pied-à-terre, LLC and trust ownership: The standard condominium framework applies. Specific house-rule limits and minimum lease terms are not documented in the records available to us and should be requested in writing.
Flip tax: Not documented in public records. Confirm with the managing agent before pricing a resale.
Assessments: An ongoing capital assessment appears in listing records. This is the single most important carrying-cost line at this address and it is not in the common-charge number.
Alterations: In a converted mill building where structure, ceiling volume and window are all part of what you are buying, the condominium's alteration rules determine what a renovation can actually be — and any exterior change, including window work and anything visible from the courtyard, requires Landmarks approval on top of the board's.
Real estate taxes: No building-wide abatement. Underwrite full unabated taxes on the specific unit.
Local Law 97
- 2024–2029 annual penalty
- $0 (under cap)
- 2030–2034 annual penalty
- $16,499/yr
- Per unit / month range
- $0 – $37
Source: NYC LL84 benchmarking and PLUTO · The Roebling Research Library. City record last verified September 2026.
See full Local Law 97 analysis — emissions history, scenarios, methodology →Facade safety — Local Law 11
The latest available FISP filing classified the facade as Safe — no repairs were required at that inspection. Facade inspections run on a fixed five-year cycle; future inspection, repair, and any assessment decisions remain building-specific.
How to read this, and where it comes from
QEWI = Qualified Exterior Wall Inspector — the licensed engineer the city requires to sign the report (the independent expert, not the managing agent).
Penalties shown are amounts DOB assessed against filings on record across 2005–10 to 2020–25. The FISP dataset does not record whether they were paid, contested or remain open, so treat the figure as history rather than a current balance and confirm the building’s standing with the managing agent.
Source: NYC DOB facade filings (FISP) · The Roebling Research Library. City record last verified September 2026.
Recent sales
444 12th Street prices as loft product inside a row-house district, and that is a different unit of account from the rest of the Park Slope market. The district's co-ops and brownstone conversions are read in rooms; this building sells square footage, ceiling height, window area and outdoor space. A comparable set drawn from six-story brick buildings on Seventh Avenue will be wrong in both directions.
Within the building, the spread is driven by whether a residence is a duplex, whether it is in the rooftop penthouse addition, whether it has a deck or balcony, whether it faces the courtyard or the street, and how much of the original fabric a given renovation preserved. Original condition photographs well and appraises as a project, and those two facts need reconciling before a number is set. Parking is a separate deeded asset and should be valued separately rather than folded into a price per foot.
Across Brooklyn, the converted-industrial segment has continued to trade on scarcity through the last complete year: the supply is fixed, contextual zoning inside historic districts forecloses replication — this building is already built to 2.30 FAR against a permitted 2.00 — and buyers who want the format have very few addresses to choose from. The correct comparable set for this address runs through Brooklyn's other landmarked factory and warehouse conversions alongside the local Park Slope set, and it should include the two neighbors on this block, which share the history and share nothing legally. Unit-level transaction history is maintained in The Roebling Research Library and shared with clients during diligence.
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.
| Date | Unit | Apartment | Price | PPSF | vs. Ask |
|---|---|---|---|---|---|
| Jun 16, 2026 | 1H2H | 2 BR · 2 BA · 1,050 sf | $1,895,000 | $1,805/sf | +0.0% |
| Feb 9, 2026 | 3B | 3 BR · 2 BA · 1,715 sf | $2,750,000 | $1,603/sf | +0.0% |
| Feb 3, 2026 | 4D | 2 BR · 2 BA · 1,120 sf | $1,800,000 | $1,607/sf | +0.0% |
| Aug 11, 2025 | 21 | 150 sf | $282,000 | $1,880/sf | off-mkt |
| Jan 24, 2025 | 4A | 3 BR · 2 BA · 1,525 sf | $2,350,000 | $1,541/sf | +0.0% |
| Nov 25, 2024 | 16 | 150 sf | $225,000 | $1,500/sf | off-mkt |
| Nov 19, 2024 | PHE | 4 BR · 3 BA · 2,420 sf | $3,990,000 | $1,649/sf | -9.3% |
| Oct 11, 2024 | 1D | 2 BR · 1 BA · 1,050 sf | $1,750,000 | $1,667/sf | -2.5% |
Market read. Most recent trades (2026) cleared a median $1,605/sf across 2 sales. Median listing discount 1.1% 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 3-01098-7510) 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.
What to know if you’re buying
Get the date right, and get it in the file. This is a c.1881 Ansonia Clock Company factory, per the LPC designation report. Widely circulated records saying 1920 are wrong. The correction is worth real money in an appraisal and in marketing.
Establish which building on the block you are buying into. The former clock-factory block holds this condominium, the cooperative at 420 12th Street (Ansonia Court), the separate condominium at 438 12th Street, and a row of 1986 condominium town houses. They share a name in common speech and nothing else. Read this condominium's financials, not the block's reputation.
Price the assessment, not just the common charge. Listing records reference an ongoing capital assessment. Ask for the amount, the purpose and the end date in writing, and add it to the monthly number before you offer.
Parking is a separate deed. Twenty-two of the 59 unit lots are parking spaces. If a space is part of the deal, confirm the unit number and that it conveys.
Underwrite four buildings and a courtyard. Façade, roof, windows, courtyard and garage across four structures, carried by 37 residences. Ask for the last two FISP filings, the reserve position and the assessment history. The cycle-9 SAFE filing in January 2024 is a genuinely good sign; read the two cycles before it as well.
Landmarks governs the windows. Arch-headed openings in a designated district. Any sash or configuration change runs through the Commission before the board sees it.
What to know if you’re selling
Lead with the courtyard and the arches. A gated landscaped courtyard entered past the factory's own perimeter wall, and 1881 arch-headed window openings, are two things no competing Park Slope listing can show. Photograph both first.
Tell the Ansonia story accurately and briefly. The world's largest clock factory, 1,300 employees on this block, the 1880 fire, the rebuild by Samuel Curtiss, Jr., manufacturing gone in 1929, apartments by 2002. It survives compression and it differentiates the listing.
Correct the 1920 date in your own copy. Buyers researching this building will find the wrong year in several places. Sellers who present the LPC designation report entry win that argument before it starts.
Anchor to loft comparables. Pull matched sales from Brooklyn's converted industrial buildings alongside the Park Slope set. Price per square foot is the language this buyer already speaks.
Have the assessment answer ready. The single most common stall in a deal at a converted loft condominium is an unexplained assessment. Written confirmation of the amount, purpose and end date removes it.
Comparable buildings
If you're considering 444 12th Street, also evaluate:
- 420 12th Street (Ansonia Court) — the larger Curtiss building on the same block, converted to a cooperative in 1982; the same fabric under entirely different ownership and policy
- 205 12th Street — South Slope condominium a few blocks west; the conventional new-construction alternative in the same submarket
- 251 7th Street (The Argyle) — Park Slope condominium off the Seventh Avenue spine
- 229 9th Street (Luna) — South Slope condominium; comparable buyer pool, purpose-built plates
- 445 5th Avenue (The Slope on Fifth) — larger Park Slope condominium on the Fifth Avenue corridor
- 343 4th Avenue (Novo) — 2006 Fourth Avenue condominium with garage parking; the closest local comparison on the parking question
- Timber House (670 Union Street) — the design-led Park Slope condominium alternative
- 214 North 11th Street (Warehouse 11) — Williamsburg warehouse conversion; the same format in a different submarket
- 85 North 3rd Street (The Mill Building) — Williamsburg mill conversion; close peer on fabric and scale
- 184 Kent Avenue (Austin Nichols House) — landmarked warehouse conversion on the Williamsburg waterfront; the borough's benchmark for the format
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.
Considering a move at Recorded and filed with the Department of Buildings as the Ansonia Muse Condominium. Market records also carry "Ansonia Clock Factory" and "Ansonia on 12th Street" for the same building?
Request a private building brief with the relevant comparable sales, current and off-market availability, and an apartment-specific view of value.
Own an apartment here? See what it would sell for.
A Private Pricing Opinion — what your apartment at Recorded and filed with the Department of Buildings as the Ansonia Muse Condominium. Market records also carry "Ansonia Clock Factory" and "Ansonia on 12th Street" for the same building 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.