340 West 72nd Street (The Chatsworth Annex)

Scharsmith designed the Annex as a deliberately restrained companion: where the Chatsworth piles on cherubs, caryatids, and stag heads, the Annex works in limestone ashlar with festooned carving, round-arched ground-floor windows with cartouche keystones, and a crown-like projecting cornice that the LPC report describes bay by bay. The shared one-story entrance pavilion between the two buildings — heavily rusticated limestone with a sculpted niche, cherubs, and garland hood mold — is one of the finest small entries on the West Side. All of it is protected: the 1984 individual designation covers both buildings and their lots, and exterior work runs through LPC, as the joint facade restoration program presented in December 2022 demonstrates.

Inside, the original eight floor-through apartments have been subdivided into roughly 23 residences, so layouts vary widely — from compact units to large multi-bedroom homes that retain the deep floor plate, high ceilings, and window rhythm of the 1906 plan. Renovation quality is unit-specific, and same-line comparables are scarce; valuation here is done apartment by apartment.

This is a small cooperative that discloses little publicly, and we treat that honestly: staffing levels, amenity specifics, and the policy stack (pets, pied-à-terre, sublets, financing limits, flip tax) should be confirmed with the managing agent at offer stage rather than assumed from aggregator listings, which intermix the Annex with the neighboring condominium's amenity package. What city records do establish: an elevator building, alterations in the 2015–2016 cycle, and an LPC-reviewed facade program in process as of late 2022 — buyers should ask how that work was funded and whether assessments attach.

Recent sales

Sales sourced from NYC Department of Finance recorded transfers (BBL 1-01183-0050) 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.

Confirm which building you are actually buying into. The Chatsworth (344, condominium) and the Annex (340, cooperative) share a landmark designation, a block, and a Google search result — and not much else structurally. Transfer taxes, board process, financing flexibility, and pricing all differ. We verify lot, entity, and offering documents at the start of diligence, not the end.

The landmark is the asset and the constraint. The 1984 individual designation plus the historic district means window, rooftop, and facade-adjacent work runs through LPC. Review the building's alteration history and the status of the 2022 facade program before contract.

Expect thin public disclosure and underwrite accordingly. A 23-unit co-op with no marketing apparatus publishes nothing. Your attorney should review several years of financials, the facade program's funding, and the full policy stack directly from the managing agent. Run the Co-op Board Qualification Calculator before offering.

Layouts are non-fungible. Subdivided floor-throughs produce one-of-a-kind apartments. View multiple lines if possible, and price against the specific unit's proportions and light rather than a building average that barely exists.

The block is the everyday luxury. Riverside Park at the door, the 1/2/3 express at 72nd and Broadway, and the landmarked streetscape in between. For park-and-subway buyers it is one of the most efficient locations on the West Side.

Tell the provenance story precisely. Scharsmith, 1906, the Johnson Kahn Company, the developer who kept the best building for himself, the 1984 designation — this is among the best-documented small buildings on the West Side, and the buyer pool for landmark pre-war responds to specifics. We market from the designation report, not adjectives.

Position against the condominium next door. The Chatsworth conversion set a renovated, amenitized price ceiling for the ensemble. The Annex pitch is the same landmark, the same block, and the same bones at a meaningful per-foot discount — with co-op mechanics as the trade.

Correct the record before buyers find the noise. Aggregator pages misdate the building, mislabel its ownership type, and blend its sales with the condominium's. A well-prepared listing preempts all three with documents. We supply the LPC report and verified building data to buyers' counsel from the Research Library.

If you're considering 340 West 72nd Street, also evaluate:

• The Chatsworth (344 West 72nd Street) — the ensemble's condominium half; the renovated, amenitized alternative at a premium
• The Dorilton — the corridor's flamboyant 1900 Beaux-Arts landmark co-op at 71st and Broadway; the closest like-for-like
• The Ansonia — the Beaux-Arts icon at 73rd and Broadway; the condominium alternative in the same architectural register
• The Apthorp — Clinton & Russell's full-block 1908 landmark; the trophy-scale condominium comparison
• 137 Riverside Drive (The Clarendon) — 1906 Riverside Drive pre-war co-op of the same vintage
• 194 Riverside Drive — boutique 1901 Riverside co-op; similar scale and park orientation
• 320 West End Avenue — Candela's 1924 West End co-op; the avenue's pre-war alternative
• 11 Riverside Drive (The Schwab House) — the post-war full-service co-op alternative two blocks south

The Roebling Team at Compass works the Upper West Side — Riverside Drive, West End Avenue, and the 70s park blocks — as a core practice area. We publish this building profile because Chatsworth Annex buyers and sellers deserve building-specific intelligence — landmark mechanics, ensemble history, and clean separation of the Annex's record from its condominium neighbor — not generic neighborhood commentary.

If you're considering a transaction at 340 West 72nd Street, a 30-minute consultation is the right starting point.