ACADIA 2013: Adaptive Architecture is the proceedings of the 33rd annual international conference of the Association for Computer-Aided Design in Architecture. The conference is held October 24-26, 2013 in Cambridge, Ontario and hosted by the School of Architecture, University of Waterloo, in partnership with the University at Buffalo, SUNY, and the University of Nottingham. The proceedings publication contains peer-reviewed and juried research on computational design focused on emerging themes of adaptive and complex systems within contemporary architecture. Papers, research and design posters, keynote presentations and ACADIA 2013 Award papers are included together with information on current organization of the society. ACADIA 2013 Adaptive Architecture is associated with the 2012 Adaptive Architecture conference held at the London Building Centre.