| Company | Timeline | Status | |
R P + K International Limited Director • Chief Executive Officer | 5 Apr 2008←2 Years 9 Months→31 Dec 2010 | Dissolved | |
| Roger Preston & Partners Limited Director • Chief Executive Officer | 5 Apr 2008←2 Years 9 Months→31 Dec 2010 | Active | |
Roger Preston Limited Director • Chief Executive Officer | 5 Apr 2008←2 Years 9 Months→31 Dec 2010 | Dissolved | |
| Trett Holdings Limited Director • Chief Executive Officer | 1 Apr 2008←2 Years 9 Months→31 Dec 2010 | Active | |
| Trett Contract Services Limited Director • Chief Executive Officer | 1 Apr 2008←2 Years 9 Months→31 Dec 2010 | Active | |
| Trett Limited Director • Chief Executive Officer | 1 Apr 2008←2 Years 9 Months→31 Dec 2010 | Active | |
| Roger Preston Group Limited Director • Director | 31 Mar 2008←2 Years 9 Months→31 Dec 2010 | Active | |
Whitelaw Turkington Landscape Architects Limited Director • Chief Executive Officer | 29 Feb 2008←2 Years 10 Months→31 Dec 2010 | Dissolved | |
| Association For Consultancy And Engineering Director • Consulting Engineer | 5 Dec 2006←3 Years→30 Nov 2010 | Active | |
| Sweco UK Limited Director • Chief Executive Officer | 1 Nov 2002←8 Years→31 Dec 2010 | Active | |
