Thermal retrofitting, refurbishment and re-use of traditional and historic building stock in Malta : a cost-sensitive, value-added approach

Abstract

The main aim of this paper was to study traditional and modern Maltese building construction methods to assess their potential contribution towards thermal retrofitting alterations to local building stock, both old and new, and to establish the payback period for such retrofit jobs, typically with a given budget. Three local case studies with similar site conditions were chosen. Detailed drawings and surveys of the existing buildings were studied and also the proposed alterations and extensions. The construction materials used and the proposed materials were assessed with respect to indoor human thermal comfort. A 3D performance model was generated using the software Integrating Environmental Solutions (IES) for the three buildings. This simulated the current status as well as the newly proposed conditions with a selection of design options, thus identifying which option would make the building more comfortable for the end user. The payback period for each alteration was eventually worked out and from the results obtained, it was noticed that roof insulation is the most cost effective option for retrofitting while external wall insulation, even though savings are considerable, is not always financially feasible to retrofit. It was also noticed that footprint, geometry and boundary conditions play an extremely important role. However, when it comes to retrofitting, although it was confirmed that site parameters are extremely important for a cost-benefit analysis, the overruling thrust of such a retrofit should strive towards improved energy efficiency and a reduced carbon footprint of the newly revamped building. Therefore, an overall balance of cost-savings and energy efficiency should be obtained for an overall truly sustainable building. This should augur well for the cost-sensitive energy-efficient and value-added refurbishment and re-use of Malta’s heritage building stock.