Life cycle cost optimization of building façade: A social housing case

In this paper, a common social housing archetype design was studied in order to improve the energy and cost performance. The focus is on evaluating the effects of some parameters of the design of the façade in particular: the size of the windows and the optical and thermo-physical properties of the components. The aim is to obtain cost optimal energy efficient scenarios in accordance with the Recast of Energy Performance of Buildings Directive (EPBD Recast) by determining efficient thicknesses of the insulation for the exterior walls and efficient window sizes and types of glazing for each orientation, simultaneously. The parameters of the façade are optimized in order to obtain the dominant values and ranges in terms of energy and cost. There are remarkable differences in the dominant options for the thickness of the insulations, as well as the type and size of windows: they depend on whether they have a north, south and east–west orientation. The decision makers should design each façade in dependence on its orientation to determine its optimal optical and thermo-physical properties in terms of its cost and its consumption of energy. A reduction by approximately 5% in the life cycle cost and 17% in the primary energy use was achieved through the optimization of the base case.