Christ & Gantenbein won the Architect of the Year award, which is given for "all-round design excellence over a body of work by an architect or architecture practice that has been in business for more than 10 years".
Recent projects by the Basel-based office include a pavilion celebrating the 500th anniversary of the Protestant Reformation in Wittenberg, Germany, an extension to Kunstmuseum Basel and the National Museum Zurich.
"This studio has built a substantial body of work and has a clearly mature portfolio," said members of the architecture master jury, which awarded the prize.
"It shows impressive craftsmanship and has mastered technology in construction. It is particularly good at using historical references to design something that still manages to feel contemporary."
Bureau Spectacular was named Emerging Architect of the Year, a title awarded for the best "all-round design excellence over a body of work by an architect or architecture practice that has been in business for 10 years or less".
The studio was established in 2008. Located in Los Angeles, it is led by Jimenez Lai and Joanna Grant.
Bureau Spectacular's built projects include the Frankie Los Angeles store completed in 2016, while conceptual projects include an indoor treehouse based on the writing of philosopher Marc-Antoine Laugier.
"This studio shows the importance of pushing boundaries in architecture by developing a new approach through conceptual combinatorics of found objects and shapes," said the judges.
"It has established an interdisciplinary discourse by working in different fields and engaging in things from academic theory and publications to music festivals," they added.
The architecture studio award winners were announced alongside studio winners for interiors and design at the Dezeen Awards ceremony in London on 27 November 2018.
Winners received a hand-made trophy designed by Atelier NL.
See all winners at www.dezeen.com/awards/winners.