31 West 21st Street

Eleven stories on a lot of roughly 5,530 square feet, carrying about 55,800 gross square feet — approximately 48,200 residential and 7,500 commercial.

Two residences on the second floor, the A and B lines; full-floor residences on floors three through eleven. The full-floor units open directly onto their own floor, which means no public corridor above the second story and no shared landing outside anyone's door. Because the lot is an interior mid-block site with buildings on both flanks, light comes from the front and rear elevations only — but the canted Chicago-style bays on the street front, which LPC identifies as an original feature of the fourth-through-ninth stories, give each residence more glass and more directional light than a flat facade would.

The top of the building has been actively developed within the landmark framework. DOB records the legalisation of a wood roof deck and a roof-level gas line in 2011, and a private rooftop terrace renovation with associated structural work in 2013; LPC issued a Certificate of Appropriateness in 2011 and Certificates of No Effect for rooftop additions in 2012 and 2013. The penthouse residence and its terrace are the product of that programme.

There is no doorman. Eleven residential owners and one commercial owner share the building, and the operating model is the small-loft-condominium model: minimal payroll, an outside managing agent, and capital work funded as it arises.

The capital posture is the thing to understand here, and we can describe it from the building's own financial statements on file. The condominium bills its owners on two lines: an operating assessment and a separate assessment for major operations and replacements. In the year covered by the statement on file, the capital line ran to roughly forty-three percent of the operating line — the building raised more than $200,000 for major repairs in a single year, against roughly $290,000 of ordinary common charges — and spent essentially all of it in the same year on major repairs and replacements. Year-end members' equity was under $140,000, of which roughly $120,000 was designated for future repairs. The building's own accountants prepared that statement as a compilation, not an audit, and expressly declined to give an opinion on it.

Read plainly: this is a building that funds capital work through recurring assessments rather than by accumulating a large reserve, and whose financial reporting is lighter than a larger condominium's. Neither is a defect in an eleven-unit building — it is how small condominiums are usually run — but both are things a buyer must underwrite rather than assume away. The exterior programme has continued since: a south-facade restoration in 2010, masonry restoration with bulkhead skylight replacement and waterproofing in 2024, and boiler replacement with a new stainless chimney liner across 2024 and 2025. Ask what those cost and how they were funded.

Because the building sits in the Ladies' Mile Historic District, exterior work carries an LPC review step ahead of DOB — visible in the permit record above — which adds both time and cost to any facade cycle.

The two addresses are two doors apart on the same block and are routinely conflated. They should not be.

31–33 West 21st Street is Block 823, Lot 7503, BIN 1015528: an eleven-story Beaux-Arts loft of 1907 by William G. Pigueron, fifty-six feet wide, converted under an Alteration Type 1 whose offering plan is dated 2001, declared as condominium no. 1215 in November 2001, containing 11 residential units with full-floor plates and a restaurant at the base.

29 West 21st Street is Block 823, Lot 7508, BIN 1015529: a seven-story neo-Renaissance loft of 1909 by James E. Ware & Sons, roughly twenty-five and a half feet wide, converted to residential use in 2008–2009 but not subdivided into condominium units until 2022, declared as condominium no. 3148 with the declaration recorded in March 2024, containing 6 residential units.

Same block, same historic district, adjoining lots — and two entirely separate condominiums whose declarations are twenty-two years apart, with different unit counts, different plate widths, different governance histories and completely different resale records. Any analysis that treats one as a comparable for the other without adjusting for those differences is wrong.

Ownership form: Condominium, with a right of first refusal on sale and lease rather than board approval.

But the application process reads like a co-op's. Management-sourced records on file with us list the package required to transfer here: executed contract, lender commitment, the standard waiver-processing agreements, an acknowledgment of the house rules, proof of income, proof of assets, a landlord reference and three social reference letters. That is materially more than a routine condominium waiver package, and it lengthens the timeline. Prepare it in parallel with contract, not after.

Subletting: Permitted with an application through the managing agent; the building maintains its own sublet application form.

Entity purchase: Permitted. The offering plan allows a unit to be owned by a corporation, partnership, fiduciary or other entity, but restricts occupancy to the individual owner or to an officer, director, shareholder, employee or partner of that entity. Buyers planning to house family members or guests in an entity-owned unit should read that clause with counsel.

Commercial unit separation: The plan bars the commercial unit from the passenger elevator entirely, restricts it to the freight elevator and service lobby under detailed conditions including timed garbage transport, allocates it 9.1 percent of service-elevator maintenance, and charges it 100 percent of its own operating costs. This is a well-drafted separation, and it is the reason a restaurant at the base of an eleven-unit building has been workable here for two decades.

Utilities: Heat and hot water in common charges; unit gas and electric billed to owners.

Landmark constraint: The lot is inside the Ladies' Mile Historic District. Window replacement, storefront work, rooftop equipment and any visible addition require LPC review; material exterior work requires a Certificate of Appropriateness.

Real estate taxes: No abatement, no exemption, no burn-off. Underwrite from the current bill on the specific unit.

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 (2025) cleared a median $1,018/sf across 1 sale. Median listing discount 2.7% 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 1-00823-7503) 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.

Read the assessment history, not just the common charge. The building's capital model runs on assessments. A monthly common charge quoted without the assessment line beside it understates the real carry. Ask for five years of billing history on the specific unit.

Ask whether the financials are compiled or audited. The statement on file with us is a compilation. Your attorney should confirm what the current year's statement is and read it accordingly.

Budget three social reference letters into your timeline. The transfer package here is heavier than a typical condominium's. It is not board approval — there is no interview and no rejection risk of the co-op kind — but it is a real administrative step.

The full-floor plate is the product. Fifty-six feet of width on a Flatiron side street, with canted bays on the street front. Compare it against twenty-five-foot conversions on the same blocks and adjust for the difference; they are not the same asset.

Confirm the certificate of occupancy. Certificates under the conversion job run from 2012 through 2017 in the records available to us. Verify the current one directly with DOB and confirm the unit you are buying appears on it.

Lead with the width and the full-floor plan. That is the structural advantage over every twenty-five-foot conversion between Fifth and Sixth Avenues, and it is documentable — LPC's own designation report records the fifty-six-foot frontage.

Distinguish the building from its neighbour, plainly. Buyers and their agents conflate 31 and 29 West 21st Street constantly. A one-line clarification in the marketing — different building, different condominium, 2001 declaration, eleven units, full floors — prevents a mispriced comparison.

Present the capital record as completed work. The 2024 masonry, waterproofing and boiler programme is a strength when it comes with invoices and a closed permit, and a question mark when a buyer finds it as an open filing.

Set expectations on the transfer package early. The reference letters and financial documentation take time; the sellers who tell buyers on day one close faster. Buyer Closing Cost Calculator.

If you're considering 31 West 21st Street, also evaluate:

• 29 West 21st Street — the adjoining building on the same block; a separate, much newer and much smaller condominium
• 4 West 21st Street — loft conversion on the same street, closer to Fifth Avenue
• 40 West 22nd Street — Ladies' Mile loft building directly behind, with the same historic-district constraints
• 15 West 20th Street — boutique Flatiron conversion one block south
• 16 West 19th Street — comparable small loft condominium in the same corridor
• 27 West 19th Street — Flatiron side-street loft conversion of similar vintage
• 22 West 26th Street — full-floor loft condominium a few blocks north
• 141 Fifth Avenue — landmarked Fifth Avenue conversion; the serviced, higher-priced alternative
• 105 Fifth Avenue — Ladies' Mile conversion on the avenue rather than the side street
• 7 East 20th Street — small Flatiron loft building east of the avenue