Cooper Apartments

The Cooper Apartments, also known as Seaside Apartments, is a historic apartment building located at 421–425 Seaside Avenue in Honolulu, Hawaii, U.S.. Constructed in 1939 during the Great Depression, the building is a distinguished example of a pre-war garden court apartment in Waikiki, embodying a transition between Streamline Moderne and the emerging tropical modern style, a fusion between Modern architecture and borrowing from Asian and South American vernacular architecture. This architectural style is characterized by its clean lines and simple aesthetic, reflecting the economic austerity of the time.

Designed by the Honolulu architectural firm of Dahl & Conrad, the Cooper Apartments exhibit characteristic features of tropical modern style blended with modest art deco-Asian decorative elements. The building's design includes white masonry walls, a low pitched hipped roof with overhanging eaves, large sliding windows with horizontal panes, and a distinctive stepped scalloped front wall. Additionally, the courtyard fireplace’s chimney and chimney cap contribute to its unique architectural identity.

It has been listed on the National Register of Historic Places since 2017.

History and architecture
The Cooper Apartments, also known as Seaside Apartments, is a distinctive example of the small garden court apartments prevalent in the Waikiki neighborhood of Honolulu before World War II. This two-story, concrete masonry edifice housed ten units arranged in an L-shape, centering around a paved, brick-walled courtyard which is accessible through a moon gate from the street. The architectural detailing extends to a cantilevered second-story lanai, corridor embellished with a wrought-iron railing exhibiting a foliate pattern, reaching upwards to the roof. The design also features fret-work doors and large sliding windows to facilitated the flow of cooling trade winds into the individual units, embodying a design responsive to Hawaii's tropical climate.

The building is a fine example of the modern design ethos of the architectural firm Dahl & Conrad. Bjarne Dahl, the senior partner, graduated from the Chicago Technical School in 1918 and worked with California architect Julia Morgan for five years. He moved to Hawaii in 1926 as the supervising architect for Morgan's YWCA project, and decided to make Hawaii his home. After a series of professional engagements, Dahl established his own office in 1935. The following year, he formed a partnership with Conrad "Connie" Conrad, a graduate in architecture from the University of Southern California who arrived in Hawaii in 1934. Their partnership, which lasted until the end of 1941 following the bombing of Pearl Harbor, resulted in a variety of architectural designs encompassing apartments, residences, and commercial buildings. Their design philosophy was rooted in a regional offshoot of modernism, a style well-reflected in the Seaside Apartments. Unfortunately, many of their architectural creations in Waikiki have been demolished to make way for larger-scale developments, but the Seaside Apartments continues to stand as a significant example of their modern design legacy in Hawaii.

The building was owned and constructed by Francis Cooper. Cooper was the owner of Hawaiian Transportation & Rock Products Company, the firm which manufactured the 4” x 16” hollow concrete blocks used in the construction of the building. The blocks were made with crushed lava rock aggregate. In addition, the company produced the water-proof concrete tile roof used in the building's original construction.

The Cooper Apartments is considered to be the best surviving example of a pre-war garden court apartment in Waikiki.

Modern usage and preservation
Following the war, the intense need for reasonably priced housing led to the construction of three and four story buildings in other parts of the city, as lots were consolidated to accommodate the larger structures that increased urban density. Originally constructed with five studio apartments on each floor of the building, all the original interior walls and ceilings have been removed through multiple building-wide renovations, shifting the building's primary function from residential use to commercial. The building was placed on the US National Register of Historic Places on August 7, 2017 owing to its embodiment of the distinctive characteristics of the local architectural period.

In recent times, a notable event in the history of Cooper Apartments was its sale along with the neighboring historic property, Seaside Hawaiian Hostel, for a collective sum of $9.5 million. This transaction, reported on October 19, 2023, highlights the continued relevance and value of Cooper Apartments in the modern real estate landscape of Honolulu.