A supporting method for selecting cost-optimal energy retrofit policies for residential buildings at the urban scale

Nowadays, in Europe, the main challenge is not only the construction of new high performing buildings, but also the promotion of proper retrofit actions on existing buildings. In the on-going transition towards low carbon cities, tools to support local municipalities are fundamental. To scale up results achieved at single buildings to group of buildings and to reflect the dynamics of the buildings stock with acceptable computational costs, new approaches are needed. This paper presents a new bottom-up methodology to aid decision-makers in the planning process; the approach enables to simulate and analyse the evolution of the building stock from an energetic, economic and social perspective over long-term horizons. The approach is based on analytic hybrid methodologies for building energy performances assessment and on Geographic Information System for the creation of a database and thematic maps. In particular, the approach: 1) identifies the cost-optimal mix of successful renovation packages; 2) identifies buildings that needs to be prioritized; 3) considers the impact of socio-economic factors on policies implementation. The method is validated through urban calibration coefficients dependent on the city energy balance. Results show that this approach can support different stakeholders in selecting specific strategies depending on the desired goals