The combination of new energy efficiency building standards and new technologies ultimately shape the building environment into a more sustainable one. However, after summarizing the current problems and partial solutions to the negative environmental impact of the building & construction sector it is clear that more has to be done to mitigate the already ongoing climate crisis.

This thesis examines an emerging method for sustainable urban planning applicable in the earlier stages of the urban design process called UBEM - urban energy building modelling. The method consist of simulating energy demand of urban design proposals and with the help of other sustainable performance simulations it will be applied of the ongoing urban planning competition Ecovillage Hannover. The goal is to identify which of the enrolled seven urban design proposals at most fulfils the criteria of a sustainable urban design. From the various assessed criteria - heating energy consumption, solar power and rainwater harvest, thermal and daylight comforts the efficiency of the heating consumption proves to be the largest CO2 contributor, hence the most important criterion of sustainability.