Solutions for Improving the Energy Efficiency of Buildings Refurbishment

Abstract

The buildings sector contributes to 30% of annual greenhouse gas emissions and uses about 40% of energy. In this scenario and regarding the sustainable concerns, different strategies and directives have been developed. However, this consumption can be reduced by between 30% and 80% through commercially available technologies.

A critical and evolutionary way of thinking about the energy (and other resources) demand, management, and supply is necessary, because there is a clear concern about irreversible impacts to the world and a scarcity of the resources as well. Energy supplies should be mostly or entirely through renewable resources and highly efficient technologies put in place to achieve solution such as nearly Zero Energy Buildings (nZEB). The strategies and the rehabilitation benefits are more and more recognised, used and increasingly considered by the stockholders. So, the aim of this article is to: critical analyse the state-of-art regarding this matter; discuss the existing solutions, directives, and strategies; and present a case study where the energy performance and the economic viability are discussed. The case study is a Portuguese building model which represents the conventional construction between 1960 and 1990. On it, three scenarios of refurbishment were tested, and their benefits and costs are presented.