310 East 23rd Street

The Foundry's structure is its history: two adjoining steel-and-concrete industrial buildings from the turn of the twentieth century, twelve stories at 310 and ten at 312, with the deep floor plates and generous ceiling heights of factory construction. The residential conversion kept the loft character of the interiors — barrel-vaulted ceilings survive in a number of apartments — while adding the amenity and service infrastructure of a full cooperative.

The apartment mix runs from studios and junior units through one- and two-bedroom lofts, with a handful of larger and combined configurations and duplex layouts at the top of the stack. The loft volume gives even the smaller units a sense of scale that conventional apartments of the same square footage lack. As with any conversion of this vintage, individual apartment condition varies widely with ownership and renovation history; buyers should underwrite each unit on its own state rather than a building-wide standard.

The furnished common roof deck, with a grill, is a genuine shared amenity that takes advantage of the buildings' massing and open surroundings on the block.

The Foundry operates as a full-service condop cooperative with an elevator, a live-in resident superintendent, central laundry, bike and basement storage, and a video intercom. The furnished roof deck rounds out the amenity set. Maintenance charges have historically run at value levels relative to purpose-built doorman inventory nearby — a function of the loft economics and the building's cost structure.

The policy framework, as reflected in public listing and building records, is the building's calling card: financing to 80%, a flip tax on resale, unlimited subletting after an initial ownership period without a board interview, and an explicit welcome for pieds-à-terre, guarantors, co-purchasers, and parents buying with or for children. As with any building, the current maintenance ranges, the precise flip-tax structure, the exact subletting waiting period, and any assessment history should be confirmed directly against the offering plan and the managing agent during due diligence. The buildings' facade has been the subject of routine pre-war exterior maintenance; buyers should review the current engineering and facade-compliance status alongside the financials.

Recent sales

Recent transfers 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. $/sf is measured on the latest sales with reliable square footage (2025): a median $1,236/sf (floor-adjusted) across 1 sale. The building has traded as recently as 2026. Median listing discount 1.5% 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 1-00928-7502). 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 on co-ops is not officially recorded, figures shown are approximate.

The condop flexibility is the headline. Financing to 80%, unlimited subletting after an initial ownership period without a board interview, and a welcome for pieds-à-terre, guarantors, and co-purchasers put The Foundry well outside the rigidity of the surrounding pre-war co-op stock. For investors and flexible-use buyers on a Gramercy budget, that framework is the reason to look here first.

You are buying loft volume at value pricing. The industrial bones deliver ceiling height, barrel-vaulted volume, and floor-plate generosity that no purpose-built residential building of comparable price matches — and it does so at a maintenance-driven price point.

Underwrite the apartment, not the building average. A turn-of-the-century conversion means condition varies widely line to line. View the specific unit and price it on its recent comparables, accounting for ceiling height, exposure, and renovation state.

Confirm the policy specifics. The permissive framework is real, but the exact subletting waiting period, the flip-tax structure, the current financing minimums, and any assessment history should be confirmed against the offering plan and the managing agent before proceeding.

Review the building's exterior and reserve position. As a pair of pre-war industrial buildings, The Foundry carries the facade-maintenance obligations of its vintage. Review the current engineering report, facade-compliance status, board minutes, and reserve position during due diligence.

Lead with the flexibility and the loft volume. The condop policy framework — financing to 80%, easy subletting, pied-à-terre and investor welcome — is the building's strongest differentiator against the surrounding co-op stock. Pair it with the loft ceilings and industrial character and you have the substance of the marketing story.

Price on the line and floor. With a heterogeneous loft stock and wide condition variation, building-wide averages compress real differences. Reference the most recent closed comparable on the specific line, and account for ceiling height, exposure, and renovation state.

Position the value economics honestly. Value-level maintenance relative to the service and amenity load is a genuine selling point — frame it directly.

Closing timelines are condop-flexible. Board approval and the condop's transfer process apply, but the permissive framework generally streamlines pacing relative to a traditional cooperative; typical timelines run 60–90 days from contract through approval to closing.

If you're considering The Foundry, also evaluate:

• 150 East 23rd Street — nearby Gramercy-edge full-service building on the same corridor
• 201 East 25th Street — nearby Kips Bay full-service cooperative
• 205 East 24th Street (The Penny Lane) — nearby factory-to-loft cooperative conversion
• 305 East 24th Street — same-cluster East 24th Street cooperative
• 309 Third Avenue (The Crystal House) — nearby full-service Kips Bay cooperative on the Third Avenue blockfront
• 200 East 27th Street — nearby Kips Bay apartment building