| 83310 | Undertaking project impact studies of waterways | |
| 83310 | Undertaking project impact studies of waterworks | |
| 97320 | Undertaking services | |
| 83310 | Undertaking technical feasibility studies of agricultural buildings | |
| 83310 | Undertaking technical feasibility studies of airfield runways | |
| 83310 | Undertaking technical feasibility studies of bridges | |
| 83310 | Undertaking technical feasibility studies of chemical and related facilities | |
| 83310 | Undertaking technical feasibility studies of civil engineering works | |
| 83310 | Undertaking technical feasibility studies of commercial buildings | |
| 83310 | Undertaking technical feasibility studies of dams | |
| 83310 | Undertaking technical feasibility studies of elevated highways | |
| 83310 | Undertaking technical feasibility studies of harbours | |
| 83310 | Undertaking technical feasibility studies of highways | |
| 83310 | Undertaking technical feasibility studies of industrial buildings | |
| 83310 | Undertaking technical feasibility studies of industrial plants and processes | |
| 83310 | Undertaking technical feasibility studies of irrigation works | |
| 83310 | Undertaking technical feasibility studies of local cables and related works | |
| 83310 | Undertaking technical feasibility studies of local pipelines and related works | |
| 83310 | Undertaking technical feasibility studies of long-distance communication lines | |
| 83310 | Undertaking technical feasibility studies of long-distance pipelines | |
| 83310 | Undertaking technical feasibility studies of long-distance power lines (cables) | |
| 83310 | Undertaking technical feasibility studies of manufacturing constructions | |
| 83310 | Undertaking technical feasibility studies of mining constructions | |
| 83310 | Undertaking technical feasibility studies of non-residential buildings | |
| 83310 | Undertaking technical feasibility studies of outdoor recreation facilities | |
| 83310 | Undertaking technical feasibility studies of outdoor sports facilities | |
| 83310 | Undertaking technical feasibility studies of power plants | |
| 83310 | Undertaking technical feasibility studies of railways | |
| 83310 | Undertaking technical feasibility studies of residential buildings | |
| 83310 | Undertaking technical feasibility studies of roads | |
| 83310 | Undertaking technical feasibility studies of streets | |
| 83310 | Undertaking technical feasibility studies of subways | |
| 83310 | Undertaking technical feasibility studies of the automation of industrial processes | |
| 83310 | Undertaking technical feasibility studies of tunnels | |
| 83310 | Undertaking technical feasibility studies of waterways | |
| 83310 | Undertaking technical feasibility studies of waterworks | |
| 53232 | Underwater work | |
| 83814 | Underwater photography | |
| 54232 | Underwater repair work | |
| 88221 | Underwear (of woven, lace, knitted or crocheted, etc. fabric) manufacturing services | |