Calum has taken London CLT from having its first site identified, to actively organising campaigns in 11 neighbourhoods, 6 of which have provisional agreements on sites, including in Tower Hamlets, Lewisham, Southwark, Croydon, Redbridge and on the Olympic Park. Calum was also previously a Senior Organiser with Citizens UK, where he trained over 400 community leaders across the UK, and he helped found Peckham Citizens. Calum guest lectures at academic institutions in the UK, holds a BArch (Part I) from the University of Sheffield and a Professional Diploma in Architecture (Part II) from the Sir John Cass School of Architecture.