Opaque façades energy refurbishment: design options and good practice

The existing building stock refurbishment is a crucial aspect in reducing the energy demand of the built environ-ment, often characterized by low performance envelopes. The paper presents a review on the main issues, con-straints and strategies for the energy, architectural and performance refurbishment of existing opaque building fa-çades, showing their application through some significant case studies, where innovative technical solutions have been used. In this regard, this paper is intended to provide a practical framework of specific recurring issues in re-furbishment projects, such as: redefinition of the main technological façade details, integration of existing solutions lacking in terms of thermal insulation performance (compared to nowadays standards), architectural constraints that prevent the intervention from the outside, fire safety, etc., giving at the same time some systematic guidelines that can be used conveniently in other similar case studies.