The decarbonisation goals for the building sector require the large-scale determination of buildings; carbon footprints. For this purpose, Life Cycle Assessment (LCA) is generally used as a methodology to determine the Global Warming Potential (GWP) of individual buildings and districts. LCA tends to be granular, requiring a large amount of data and time. This work introduces Teco, an enrichment framework for heuristically determining the carbon footprints of districts using City Geography Markup Language (CityGML) Level of Detail (LoD) two building models along with a few manual input parameters. In this paper, a use case demonstrates the necessity for refinements of available archetypes and user input for an accurate calculation of the GWP.