Bottom-up modelling of continuous renovation and energy balance of existing building stock: case study Kočevje

A dynamic bottom-up model of the building stock is developed and implemented in a case study of Kocevje urban region. In the model, national register of real estate is cross-linked to data from other registers, e.g. the energy performance certificates (EPC) and the subsidized energy renovation measures. Regular updates of the data in registers enable continual improvement of the model. Therenovation potential is determined with respect to the age of building components after the last renovation, while the energy performance of the building stock is based either on the EPC for a particular building if available or on the energy indicators of corresponding building type from IEE EPISCOPE building typology and IEE RePublic_ZEB. Thus, the bottom-up model of the building stock (BuilS) enable a profound overview of the total heat demand, final energy use and CO2 emissions of the entire stock. In the case study Kocevje, various strategies for improving the buildings towards more sustainable ones are presented with projections to 2030. The strategies, reference and intensive renovation scenario, are compared with more ambitious strategy that the municipality is looking towards in the frame of Covenant of Mayors commitment. The bottom-up model was validated against the metered energy use of buildings connected to district heating. In the case study the model shows how the implementation of various strategies lead to different impacts and how the ambitious municipal plans are going to produce independence from fossil fuels by fostering the use of wood biomass as a locally available sustainable energy supply. The Kocevje case study analysis demonstrates, at the local level how a concept of increasing renewable energy sources utilisation and building energy efficiency stimulated by progressive measures can respond to low carbon society and sustainable energy selfsupply challenges.