Unfortunately, we couldn't find any sources confirming the existence of Hồ Đắc Cáo as an architect of the central Vietnamese city of Huế. According to a posting in the Meta platform's group "Vietnamese Modernist Architecture" by Nguyễn Ngọc Sơn it is stated that he together with Jacques Alphée Lagisquet were the architects of the Cercle Sportif in Huế and Hồ Đắc Cáo was an Architecte Diplômé et Agréé Par Le Gouvernement (D.A.P.L.G.). But we cannot provide a verified source yet.