Kamehameha V Post Office Building

44 Merchant Street
Architect: J. G. Osborne (architect and builder)
Style: Renaissance Revival

The two-story Kamehameha V Post Office Building was designed by J. G. Osborne, who was noted for his brickmaking. Construction began in 1870 and took a year to complete. Osborne used an experimental method of concrete blocks and iron rods seen in his hometown of Yorkshire, England. During construction, the concrete blocks were constantly wetted to so they could dry slowly and create stronger walls. The old Kamehameha V Post Office is the first building in Hawaii, and the oldest in America, to have been built of reinforced concrete. Towards the end of construction, Osborne was asked to create an additional floor, but he refused.

The building was shared by the post office, the Hawaiian Gazette, and other small companies that needed office space. In 1894, the post office took over the building and was the only tenant.

In 1900, a two-story extension was added to the back of the building. The new portion was made of lava stone and brick with a cement plaster on the exterior to match the existing design.

The Kamehameha V Post Office Building served as Honolulu's main post office until it moved to the Federal Building in 1922. Shortly after, the building was renovated and used as a postal sub-station, as well as space for the Territorial Tax Office. In 1946, the district courts took up residence in the building, and a portion of the portico on Merchant Street was enclosed for more office space.

The building stood in disrepair for many years throughout its usage, and the second floor was deemed unsafe multiple times. It wasn't until 1993 that the Kamehameha V Post Office Building was fully restored and renovated for theater usage. During the renovation, the attic had been converted into a third floor, and the 1946 additional walls had been removed. Since then, the Kamehameha V Post Office Building has been home to the Kumu Kahua Theatre.