Double- or Single-Skin Façades for Low-Carbon Office Refurbishments in the UK: A Comparative Case Study: Fid-Bau Portal

Double- or Single-Skin Façades for Low-Carbon Office Refurbishments in the UK: A Comparative Case Study

Pomponi, Francesco / Piroozfar, Poorang A.E.

In the UK, 75 % of non-domestic buildings will still exist in 2050, and the reduction of their emissions represents a major challenge for the UK government to meet the greenhouse gases (GHG) target. There is a growing tendency towards the use of double-skin façades (DSFs) for office refurbishments in Europe. In renovations, a DSF consists of an external glazed skin added in front of the primary building envelope and separated from it by an air cavity. DSFs have the potential to act as a thermal buffer in winter and enhance the performance of natural ventilation in summer, thus potentially reducing the energy consumption for heating and cooling in buildings.

Limited knowledge exists about DSFs for office refurbishments and, more specifically, the literature lacks comparisons between this technology and high-spec single-skin refurbishments. A case study has therefore been selected to address this gap and compare the performances of the two technologies. This chapter reports findings from the study of a cellular office building of the University of Brighton that is currently undergoing a major refurbishment. The case study is analysed with three scenarios: the building as it was, as it will be once the refurbishment is completed and as it could have been with a DSF. Detailed modelling and related energy figures are achieved by means of building energy simulation tools and compared against energy benchmarks.

Results show that DSFs are a viable option for refurbishing existing office buildings. The reduction of energy consumption with the double skin outweighs that achieved with the single-skin refurbishment. Additionally, comfort analyses for all the scenarios considered showed that the risk of overheating with the double-skin façade could be avoided by the use of shading devices to make sure that the energy reduction is not at the expense of the building users’ comfort. This study contributes towards deepening and broadening the knowledge about performances of DSFs within a refurbishment context and their potential advantages over high-spec single-skin alternatives.