Generating an analytical energy model

Methods, systems, and apparatus, including computer programs encoded on a system, for generating an analytical energy model from a conceptual representation or a mass form model. In one aspect, actions include receiving a conceptual representation of a building including one or more user-defined floor levels and multiple surfaces defining volumetric space, and, responsive to a request to generate an analytical energy model, automatically generating the analytical energy model by: deriving geometric information from the conceptual representation; defining one or more mass volumes; algorithmically assigning one or more surface types to mass volume surfaces; defining one or more thermal mass zones based on the mass volumes and a corresponding number of user-defined floor levels; deriving thermal properties of the one or more thermal mass zones; and combining the defined one or more thermal mass zones, the derived thermal properties, and predefined analytical energy model parameters to generate the analytical energy model.