Optimisation of the refurbishment of single-family homes based on construction era

In the last ten years Germany has met less than half of its renovation quota annually. This study aims to create a roadmap for German renovation by identifying the construction era of single-family homes which has the greatest potential for decarbonization. A multi-objective optimization was conducted which varied the building envelope and energy systems while optimizing for annual cost and carbon emissions. The optimization was carried out in oemof.solph and PyGMO on typical German building stocks from 11 different construction eras between 1860 and 2020. The buildings were modelled in TEASER using TABULA building stock data. It was found that by spending the same amount of money annually as the business as usual case, the post-war construction era represents the highest potential for improvement. Additionally, if all construction eras are fully renovated from before 2008 over 90 megatons of CO2 emissions could be saved annually. Lastly, the electrification of the energy system and removal of fuel-based energy production was the primary outcome for both the most ecologic and most economic Pareto solutions, across all construction eras