| Company | Timeline | Status | |
| Hirst Architecture Limited Director • Conservator | 3 Nov 2023←2 Years 2 Months→Current | Active | |
| Hirst Heritage Limited Director • Conservation Specialist | 2 Mar 2022←3 Years→Current | Active | |
| Corringdon Limited Director • Architectural Conservationist | 27 Jun 2016←9 Years→Current | Active | |
| Hirst Conservation Limited Director • Conservation Consultant | 28 Sep 2015←10 Years→Current | Active | |
Hirst Conservation Materials Limited Director • Partner Hirst Conservation | 15 Jul 1992←24 Years→27 Sep 2016 | Dissolved | |
