Life Cycle Assessment of building energy systems on neighbourhood level based on semantic 3D city models

This study presents a method which allows conducting an energy and emission related Life Cycle Assessment (LCA) and cost-related Life Cycle Cost Assessment (LCC) of large residential building stocks focusing on selected heating system components. Using this method the status quo as well as two refurbishment scenarios for an entire neighbourhood with 196 residential buildings in Munich, Germany, is assessed. Within the status quo and the refurbishment scenarios, among other things, the use of different energy systems and energy standards of the building envelope are investigated. CityGML semantic 3D city models serve as a source of building-specific information for these assessments. The results show that even if all residential buildings are refurbished to passive house standard and powered by renewable energies by 2035, life cycle-based energy demands and emissions will still be present, that counteract the goal of achieving climate neutrality. In addition, the life cycle-based costs exceed the savings achieved by the refurbishment. The developed method is implemented in Java which provides on the one hand a new approach to assessing building stocks on a life cycle basis and on the other hand its transferability. This results in innovative evaluation and assessment possibilities for political and municipal decision-makers.