After the Charles Rennie Mackintosh Society (CRMS) was able to purchase the Queen's Cross Church (QXC) from the Church of Scotland in 1999, it planned to build an extension in a gap site adjacent to the church housing the CRMS and meeting visitors' requirements... The following report draws on McKA's analyses of QXC, which I further developed with my own ideas. In addition, David Mullane, the former director of the CRMS, and a CRM and QXC authority, acted as my 'client' for this project.