David Sandved enrolled at the Norwegian Institute of Technology (NTH) in 1933. For his final exam project in 1937, Sandved designed a functionalist building characterized by an open ground floor and a curved top floor with a light sign that read "Konserthuset - I aften dirigerer Dobrowen verker av Fartein Valen" ("The Concert Hall - Tonight Dobrowen conducts works by Fartein Valen").
In 1938, Sandved, along with Jonas Hidle, was awarded for their proposal for the Norwegian pavilion at the World's Fair in New York, "Building The World of Tomorrow," 1939-1940. The entry, titled "Tail," was described by the jury as "appealing with a good grouping and successful material treatment." Between 1938 and 1940, Sandved collaborated with architect Th. Frost in Oslo and had the Apotekerbygningen in Oscars gate 19 built in 1939. The commercial building is listed on the City Antiquarian's yellow list and designated for special preservation.
Sandved worked as an assistant at the architectural firm Egeberg in Oslo from August 1940 to March 1943. In 1941, due to disagreements with Egeberg, he sought to leave the architectural firm. In addition to his own architectural practice from 1943, he tried to support himself and his family through various odd jobs involving rose painting and playing the piano. During this time, he released a jazz hit titled "Hvor skal vi gå hen etterpå" ("Where should we go afterwards"), recorded with Fred Thune's orchestra and Inger Jacobsen. During World War II, he also worked as a courier for the Allied intelligence organization XU.
In 1948, Sandved moved to Haugesund to work as an architect for Haugesund Mekaniske Verksted. Between 1948 and 1949, he designed the conversion of two American submarine chasers into passenger ships MS "Sognefjord" and MS "Sunnfjord." On behalf of AS Stord, he designed the interiors of MS "Jylland" in 1949. In 1958, the Danish ferry MS "Skagen" was furnished in Kristiansand based on Sandved's drawings. The architect also executed numerous ship interiors for shipowner Christian Haaland's line boats in Concordia Line. In total, the architect completed around 30 different ship superstructures with interiors and furnishings.
Sandved established his own office with architect Odd Volle as the first assistant in 1951. The firm gradually expanded, and the office completed various residences, commercial buildings, and public structures in the West, including the Haugesund Public Library from 1965 to 1967 and the Haugesund Art Gallery from 1978. Haugesund Public Library was designated a protected cultural monument by the Norwegian Directorate for Cultural Heritage on November 15, 2019, as an outstanding example of modernist architecture and a cultural heritage of national value.
Over the years, Sandved's architecture evolved from functionalism, new monumentalism, critical regionalism, to Scandinavian, Goetheanist architecture in later projects for the Steiner School in Haugesund. In the 1950s he was strongly influenced by Rudolf Steiner and his anthroposophy. Sandved also participated actively in the public sphere, defending the composer Fartein Valen and his atonal polyphonic music in the local newspapers.
David Sandved retired in the 1980s, and the architectural firm David Sandved Arkitekter M.N.A.L. changed its name to Sandved and Wathne A/S. Architect Einar Wathne graduated from NTH in 1966 and worked with Sandved until 1981 when he took over the firm.