After graduating from the University of Laval School of Architecture in 1983, Guy Courchesne's architectural career began in St-Hyacinthe. In partnership with architects Sylvain Allaire and Alain Bergeron, he founded the firm ABCP Architecture in 1987, in association with Serge Perras. With ABCP, Guy Courchesne was in charge of the firms general management and business development which allowed him to oversee the expansion of the firm to other cities including Montréal, Québec City, Jakarta, and Beijing in 2004.
In 2006, with architects Sylvain Allaire, Benoit Dupuis and Maxime Frappier, he co-founded a cd f* architecture-urbanisme-intérieur. Today, Guy Courchesne is again fulfilling the role of the firms general manager and is in charge of business development. The firm now employs 50 professionals with offices in Montréal and St-Hyacinthe.