This paper reports a study that has been undertaken as part of an on-going project to examine the capacity of 3D city models to support thermal design of building. The two standard used for this is CityGML and gbXML. The first is an OGC standard for the exchange of 3D city information, and the second is a CAD standard to exchange of information between engineering and environmental analysis software. In particular, our premise is that effective thermal design relies on the ability to exchange urban environment information such as surrounding building, green areas, streets, trees. CityGML is a 3D information model that provides a detailed information about the topography and manmade objects - surrounding environment data in a robust way using an open information standard GML. The focus of this present work has been on the processes involved in design with the urban context and how it could affect the design workflow for advising on thermal performance issues. We begin by looking at the kinds of data that needs to be exchanged to support such design in context. We then test the exchange using a pilot project model and finally review the capacity of the CityGML standard to support such processes.