Sustainable refurbishment: quantifying the impact of façade changes in multi-storey, multi-occupancy buildings

Building refurbishment is key to reducing the carbon footprint and improving comfort in the built environment. However, quantifying the real benefit of a facade change, which can bring advantages to owners (value), occupants (comfort) and the society (sustainability), is not a simple task. At a building physics level, the changes in kWh per m2 of heating / cooling load can be readily quantified. However, there are many subtle layers of operation and maintenance below these headline figures which determine how sustainable a building is in reality, such as for example quality of life factors. This paper considers the range of approaches taken by a façade refurbishment consortium to assess refurbishment solutions for multi-storey, multi-occupancy buildings and how to critically evaluate them. Each of the applied tools spans one or more of the three building parameters of people, product and process. ‘Decision making’ analytical network process and parametric building analysis tools are described and their potential impact on the building refurbishment process evaluated