Evaluating the payback period and embodied energy in comparison to thermal insulation of different types of roof construction

Abstract

The aim of the study is to identify the most thermally efficient roof from selected specimens, while also taking into consideration the overall costs of construction and embodied energy consumed. The test were carried out in lab conditions with the specimens tested representing a traditional roof, insulated roof, ventilated roof and an insulated roof remedial measure. These specimens cater for the types of energy efficient roofs mostly used in the Maltese Islands. Results suggest that the insulated roof is the most thermally efficient and the thicker the insulation the more efficient it becomes. However, this conflict with its resulting capital costs incurred and embodied energy used, as it was shown that the remedial measure would be the most expensive. It is not always feasible to install the highest U-Value insulation due to the high increase in cost and embodied energy consumed compared to the increase in thermal efficiency to thickness ratio. The designer has to keep in mind the needs of his structure so as to try to achieve the best solution in terms of all of the criteria.