Combining environmental impact and financial cost calculations with quality assessment at the building level

Buildings are complex products whereof most important design decisions are taken during the first design phase. Environmental impact (EI) and financial cost (FC) are therefore preferably evaluated at this moment. The complexity of buildings and the lack of information during the early design phase however make the evaluation difficult. In this paper a methodology is proposed to overcome these difficulties by incorporating EI assessment in the element method for cost control. This enables, in a first step, to evaluate the initial EI and FC of building elements, whereof the relation to the building is taken into account by expressing the EI and FC per m2 floor area. A building is in that sense simplified to independent elements and the lack of information is handled by refining rough first estimations to detailed calculations - for the elements of interest - later on in the design process. Moreover the aim is to include the whole life cycle of the building. Life cycle assessment (LCA) and life cycle costing (LCC) are combined, leading to a total EI and FC per m2 floor area. To enable comparative analysis, a final step is added: a quality evaluation is elaborated via a multi-criteria analysis. The proposed methodology is illustrated by a case study to improve comprehensiveness and prove its viability.