The building was the world's first example of capsule architecture built for actual use. The building is still in use as of 2010, but has fallen into disrepair
The building is actually composed of two interconnected concrete towers, respectively eleven and thirteen floors, which house 140 prefabricated modules (or "capsules") which are each self-contained units. Each capsule measures 2.3 m (8 ft) × 3.8 m (12 ft) × 2.1 m (7 ft) and functions as a small living or office space. Capsules can be connected and combined to create larger spaces. Each capsule is connected to one of the two main shafts only by four high-tension bolts and is designed to be replaceable. No units have been replaced since the original construction.
The original target demographic were bachelor salarymen. The compact apartments included a wall of appliances and cabinets built in to one side, including a kitchen stove, a refrigerator, a television set, and a reel-to-reel tape deck. A bathroom unit, about the size of an aircraft lavatory, is set into an opposite corner. A large circular window over a bed dominates the far end of the room
Construction occurred on site and off site. On-site work included the two towers and their energy-supply systems and equipment, while the capsule parts were fabricated and the capsules were assembled at a factory.
The capsules were fitted with utilities and interior fittings before being shipped to the building site, where they were attached to the concrete towers. Each capsule is attached independently and cantilevered from the shaft, so that any capsule may be removed easily without affecting the others. The capsules are all-welded lightweight steel-truss boxes clad in galvanized, rib-reinforced steel panels. After processing, the panels were coated with rust-preventative paint and finished with a coat of Kenitex glossy spray.
The cores are rigid-frame, made of a steel frame and reinforced concrete. From the basement to the second floor, ordinary concrete was used; above those levels, lightweight concrete was used. Shuttering consists of large panels the height of a single storey of the tower. In order to make early use of the staircase, precast concrete was used in the floor plates and the elevator shafts. Because of the pattern in which two days of steel-frame work were followed by two days of precast-concrete work, the staircase was completely operational by the time the framework was finished. On-site construction of the elevators was shortened by incorporating the 3-D frames, the rails, and anchor indicator boxes in the precast concrete elements and by employing prefabricated cages.
On April 15, 2007, the building's residents, citing squalid, cramped conditions as well as concerns over asbestos, voted to demolish the building and replace it with a much larger, more modern tower. In the interest of preserving his design, Kurokawa proposed taking advantage of the flexible design by "unplugging" the existing boxes and replacing them with updated units, a plan supported by the major architectural associations of Japan, including the Japan Institute of Architects; the residents countered with concerns over the building's earthquake resistance and its inefficient use of valuable property adjacent to the high-value Ginza. A developer for the replacement has yet to be found, partly because of the late-2000s recession.
Opposing its slated demolition, Nicolai Ouroussoff, architecture critic for The New York Times, described Nakagin Capsule Tower as "gorgeous architecture; like all great buildings, it is the crystallization of a far-reaching cultural ideal. Its existence also stands as a powerful reminder of paths not taken, of the possibility of worlds shaped by different sets of values."