Sede Nacional del Colegio de Arquitectos de Chile, Historical monument on Avenida Libertador Bernardo O'Higgins, Santiago, Chile.

The Sede Nacional del Colegio de Arquitectos de Chile stands at Alameda 115, on the Avenida Libertador Bernardo O'Higgins. Luciano Kulczewski designed it in 1920 in art nouveau style with modernista elements, built in reinforced concrete. Native fauna figures in stucco, plaster and stained glass decorate the facade, whose symmetrical openings use several arch types and balconies; its undulating design draws on the Casa Tassel, the Castel Béranger and the Casa Lleó Morera.

Construction was completed in 1920 under architect Luciano Kulczewski García, with the building initially serving as mixed-use residential and commercial space. It later housed a maternity clinic before eventually becoming the institutional home of the architectural organization.

The building's name honours Gonzalo Mardones Restat, the architect who in 1974 merged the former homes and shops into a single headquarters with one entrance and staircase. Its stucco, plaster and stained-glass decoration depicts native fauna, and the stained-glass restoration began in November 2016.

The building is located on one of Santiago's main thoroughfares, making it easy to spot and access via public transport. Its position on a central avenue allows visitors to appreciate the facade and surroundings without difficulty.

The facade features undulating cornices and decorative elements that resemble foliage, reflecting early modern craftsmanship from the period. Visitors often overlook these subtle details, yet they define much of the building's character and appeal.