| Company | Timeline | Status | |
| Lyall, Bills And Young Limited Director • Architect | 14 Oct 2011←14 Years→Current | Active | |
| Architectural Association (Incorporated) Director • Architect | 9 Jun 2005←3 Years→31 May 2009 | Active | |
Riba Trust Limited Director • Architect | 12 Feb 2003←4 Years→30 Jun 2007 | Dissolved | |
| John Lyall Architects Limited Director • Architect | 20 Dec 1991←29 Years→9 Sep 2021 | Dissolved | |
