The Park Avenue co-op, the York Avenue tower, and the pied-à-terre.

Lenox Hill keeps the name of a farm — Robert Lenox's, bought when this was countryside — and almost nothing of its shape. What grew on it instead is the most layered stretch of the Upper East Side: prewar co-ops on Fifth, Madison and Park; rowhouses and small conversions on the side streets between Lexington and Third; and, east of Second, a wall of postwar and newer towers running down to the hospital corridor along York Avenue. Walk four blocks here and the housing stock changes three times. The wardrobes inside it do not change nearly as much, which is where the work begins.

The Park Avenue co-op is the reference apartment. Drawn in the teens and twenties, it gave the household a formal living room, a dining room, high ceilings, deep window reveals and a back hall with a maid's room — and, for clothing, one shallow reach-in per bedroom and a coat closet by the door. The architects assumed trunks and an armoire; the current owners have neither. Building into that apartment means building into wood lath and three coats of plaster that have settled for a hundred years, so we stand our casework as furniture on the floor rather than hang it on the wall, and we scribe to crown and base instead of cutting them. It is also the honest reason a made-to-measure closet earns its keep in these rooms: a wall that loses half an inch over its run turns a bank of stock panels into a row of tapering shadow gaps, which is why we draw and mill each piece to the room instead of ordering it to a catalog dimension.

The side streets are a different problem in the same idiom. Between Lexington and the river the blocks hold narrow rowhouses, small walk-ups and converted brownstones, including the Treadwell Farm Historic District on East 61st and 62nd, where the façades and their trim are protected and the interiors have been reworked a dozen times over. These are the apartments with a chimney breast in the corner of the bedroom, a party wall that bows, and a hallway just wide enough to be useful. Storage there is won in inches — a full-height press in the dead run of a hall, a wardrobe wall built around the bump rather than beside it. The prewar joinery problem is at its most concentrated in buildings this small.

East of Second Avenue the geometry relaxes and the schedule tightens. This is the medical quarter — the hospitals along York and the East 60s and 70s — and its apartments belong to households that run on call schedules and to owners who are here two or three nights a week. Both want the same thing from a closet: everything visible at once, nothing stacked behind anything, and a drawer bank that works at five in the morning without waking the room. In postwar towers the rooms are square and the walls are drywall on studs, so the constraint is not plaster but height: the soffit line and the twenty inches above the old rod, which a full-height reach-in reclaims outright. When a second bedroom is standing in as an office and a wardrobe, we draw it as one elevation rather than two.

Where a plan gives up a room — the maid's room off the back hall, a small third bedroom above Park — it becomes a dressing room with an island, and the co-op board becomes the other half of the job. Alteration agreements in these buildings are thorough: insurance riders, work-hour rules, a managing agent who has read every variation. Every piece is designed in 3D and milled in our own Bronx workshop at 382 Canal Place in Mott Haven, then dry-fit before it ships, so our install window is measured in days rather than weeks — the difference between an approved alteration and a deferred one in an occupied building. The crew that measures the apartment is the crew that installs it; we have never subcontracted a job, and we have worked this way since 2008. The cabinetry carries a twenty-five-year guarantee.

Budgets follow the apartment. A rebuilt bedroom reach-in begins around $3,500; a dressing room carved out of a maid's room runs into the tens of thousands, and we publish how the pricing works rather than make you ask. The neighboring guides — the wider Upper East Side and the borough page for Manhattan — cover the ground around this one. The first conversation is sixty minutes, at the apartment or at the workshop: $350 flat, credited to your project. Bring the floor plan if you have one.