Almost all work to date in the field of Building Information Modelling (BIM) tools has developed software for building professionals: designers, constructors, and operators. However, another important group of potential users is the public. Use cases fall into two broad categories. Pre-construction applications span the design phase and all forms of public engagement during design development, from traditional user-feedback/community engagement processes to innovative applications such as crowd-source design. Post-construction applications include a variety of occupant-centric scenarios, including building dashboards, occupancy-assessments, etc. The relevant technology spans both BIM and social media. The Green 2.0 project aims to develop a middle-ware platform to support a range of BIM-to-public applications, with an emphasis on building energy performance and related “Green” applications. By analogy, if Facebook is conceived as a platform for a public-to-public interaction, and Google Maps as a platform for public-to-geospatial interaction, then the Green 2.0 project aims to provide a platform for public-to-building interactions. This paper describes the problem domain and preliminary work to develop the pre-construction and post-construction application areas for the Green 2.0, BIM-to-Public platform.