834 Fifth has 24
apartments on 16 floors. The building occupies a plot of land which is approximately 150' by 110', allowing for very spacious units. The building's apartments typically range in size from approximately to with an average unit being approximately 6,000 square feet. The largest single unit—a combination of two apartments done during the construction process—is approximately . The original design for 834 called for a midblock 120-foot-wide building, but it was asymmetrically extended southward during construction after a holdout corner mansion was acquired by the developer. Because this happened with the steel frame of the building's structure already in place, the extra 30 feet of frontage would be allocated as a line of duplex apartments, so that the original developer blueprints remained more or less intact. All the apartments were designed with high ceilings, and several units have outdoor space. Apartments in the building have ceiling heights of 11 to 12 feet in the public rooms, while the bedroom floors have ceiling heights of 9 to 11 feet (9 feet in the duplexes and 10 to 11 feet in the simplexes). There are three
maisonette apartments, units which have entrances from the street as well as from the building's interior
lobby. The duplexes on the southern side of the building form the A Line, each unit of which is approximately 5,500 square feet. These apartments typically have a 600-square-foot living room facing Central Park, and a 450-square-foot dining room and 300-square-foot library along the 64th Street side of the building. Most of these units have four to six bedrooms on their upper floors. Unit 13-14A is 4,750 square feet (as well as approximately 350 square feet of terraces) and Unit 15A is a 2,000 square foot simplex type apartment with approximately 250 square feet of terrace space. Several of the A-Line units have annexed space from adjoining apartments resulting in units that are over 6,000 square feet. In one case, the A-line duplex unit on the 7th and 8th floors was combined with portions of two adjacent B-line units to create the largest apartment in the building, an approximately 10,000-square-foot unit. The other apartments in the building form the B and C lines. In the original building there were two duplex maisonettes, the southern one measured roughly 6,250 square feet, while the smaller northern about 5,500 square feet. Above there were two large duplex units, about 7,000 square feet each. With the additional area available when the building was expanded to 64th Street, the developer created a total of three duplex maisonettes of 5,500, 4,500 and 6,250 square feet in total. The 6,250-square-foot maisonette was modified to enlarge the lobby. Above these maisonettes were the other B and C lines units. On the third and fourth floors are duplex B and C units of approximately 7,000 square feet each. Floors 5, 7, 9 and 10 contain smaller B-Line simplex units. These smaller apartments have Central Park-frontage of approximately 60 feet on each floor. The rest of the building's B-line apartments have a linear expanse of 120 feet of park frontage. Floors 6, 11 and 12 have only one B-line apartment, each of which is 6,500–7,000 square feet (the higher the floor the smaller the square footage due to setbacks and terraces in rear courtyard facing side of each apartment). Floor 8 also has one B-line apartment, but it is smaller due to space annexed into duplex 7-8A. In the C-Line, Floor 5 features a smaller simplex unit, 5C, and Floors 9 and 10 feature a larger duplex unit, 9-10C, with a similar footprint to the C-line duplex on the third and fourth floors. Unit 13B was originally laid out as a four-bedroom duplex, but its upper level, which contained 2 bedrooms, was annexed to become part of the original penthouse (bought by Hugh Baker for $275,000 in 1930). Unit 13B is now a smaller 5,000 square feet two-bedroom simplex unit (including several Park and north-facing terraces). Finally, at the top of the building, the triplex penthouse is 8,000 square feet, with private rooms on the 14th floor, public rooms on the 15th floor, and a sun room/library on the top level of the unit. The penthouse also features an additional 4,000 square feet of outdoor space (terraces, patios). It was expanded by Wallace K. Harrison for
Laurance Rockefeller. There is also a 1,000-square-foot superintendent's apartment on the ground floor at the rear of the lobby. ==Residents==