An investigation into the feasibility of timber construction in Malta when compared to traditional Maltese construction

Abstract

Our generation is currently facing one of the most pressing difficulties which is climate change. These difficulties are tackled by setting sustainable development goals, but most countries are still struggling to achieve the high degree of performance required to be considered sustainable. The built environment is seen as a contributor of a large chunk of the CO2 emissions. Hence, the main aim of this dissertation is to check the feasibility of other types of construction, which are more sustainable in terms of their environmental impact, when compared to traditional Maltese methods of construction. This study was based on the feasibility of timber construction (CLT) in Malta and the main factors considered were: cost, time, energy performance, structural area, demolishing waste, embodied energy and CO2. A residential dwelling in Mosta, Malta was the case study chosen for this study, consisting of a -1 basement level, 4 storeys classified as mixed use, and a receded penthouse overlying the 4th storey. Two different structural solutions were considered, one in concrete and one in timber. The concrete structure was designed and built by an independent architect, whilst for the case of timber; it was based on a lump sum given by a foreign contractor indicated as contractor A. This study was based on a quotation of a single contractor as most of the timber manufactures that were contacted, failed to send a quotation for such job. All eight factors mentioned above were taken into consideration for each case, and their differences were converted into costs, except for the embodied energy and Co2 differences. These factors were divided into 2; type 1 being instantaneously affective factors, which took into account: costs, time and structural area differences; type 2 being after a 50 year life period which took into account: cost, time, energy thermal performance, structural area, demolishing waste and compound interest rate on the difference in capital costs. The difference in embodied energy and CO2 between the two structural solutions was not considered, because of the lack of tax emission incentives for construction available in Malta. Three different results were obtained from this study. Result one, shows that the capital costs needed for CLT construction is much higher. CLT was found to cost 313 €/Sqm and 168€/Sqm for concrete. Result two, took into consideration the running costs where it shows that CLT and concrete construction would even out any initial costs difference after 48 years. This means that CLT construction would be the better choice after 48 years and over. Change in running costs was computed by doing an EPC certificate on a single unit of this project. Result three shows that concrete still would be the cheaper solution when taking into account a fixed income rate, when investing the change in capital cost at the project’s initiation. Looking from an environment impact point of view, CLT construction by far surpasses concrete construction, both at construction and operational phase. This study shows that end of life decision could be of great influence on the embodied energy and CO2 emissions for CLT construction.