Multi-objective planning of building stock renovation

The energy consumption of residential buildings represents a relevant portion of energy use at the global level. In some regions of old Europe, a large portion of the residential building stock was built in an era of low energy prices, without much attention to energy efficiency, local pollution, and greenhouse gases emissions. Today they can be renewed with energy-saving measures providing consistent benefits to the economy, air pollution, and climate. The paper shows how such energy-saving measures can be optimally planned when dealing with a regional domain, that presents a wide variety of urban conditions, construction styles, and localizations. The study builds upon the extensive dataset of individual building characteristics developed by Lombardy region in Northern Italy and proposes a plan that implements the regional directives already in force. The approach is based on the solution of a mathematical programming problem with two objectives. An efficient compromise solution is then selected considering all economic and environmental impacts. Such a preferred plan determines which actions should be undertaken, on which building types and in which municipality. The results suggest that the regional authorities should complement the current national policy with more specifically directed actions.