It is critical to note at this stage that assumptions are made related to the stage of development. This is a cost-effective way of developing ideas and concepts without committing more money or resource than is merited.
The significance of these assumptions will change over time and it is important to understand what that means on a case by case basis. For example, for early stage work 3 ideas may be developed into concepts which all involve groundworks and construction work to deliver the outcomes.
These may all appropriately have an assumption that there are no unusual ground conditions. This would not normally be tested with ground or site investigations until there is a level of design that requires such information.
However, the promoter may be aware that one of those ideas is proposed on flood plain or in an area with historic mine workings. It would be appropriate to consider that whilst the assumption still holds, that the likelihood is higher that it matures into a risk of poor ground conditions and then into scope to mitigate the ground conditions. The significance of this may be minor or catastrophic to a project therefore it is important to consider which assumptions are highly significant at an early stage.
The assumptions assessment and significance tool will give you an early indicator of questions to ask and potential impacts and significance.