Digitisation of sites can be extremely useful for a project. This provides a crucial first step in the conceptual examination and analysis of site wide design opportunities and constraints. We commission high definition aerial survey scans of development sites which are converted to accurate 3D geometric site context. Our BIM authoring software integrates with these 3D surveys to overlay development opportunities for the site. Analysis of sites include site constraints and in particular: floor space ratios, over shadowing analysis and access to light analysis.