The construction industry and the scientific community continue to seek for innovative approaches that can estimate the level of sustainability to be achieved at the end of the project from the early design stages. One of the tools developed for this purpose is Building Information Modelling (BIM), which represents the state- of- the- art tool for bringing together different expertise and achieving optimal designs at an early design stage for the maximisation of their impact. However, the level of the prospect of this tool has not been fully exploited. This paper integrates BIM with an established methodology for assessing a product’s or a system’s environmental performance- Life Cycle Assessment (LCA)- in an attempt to maximise the benefits from this synergy and achieve the most sustainable constructions. The impact from the integration of these two valuable tools is presented for a water supply system using case studies for a range of different materials. Comparison of a modern Vernetztes Polyethylen (VPE) water supply system against two systems made from traditional materials (steel and copper) was made. The results of this study show that a VPE water supply system performs 87% better than the steel system, and 88% better than a copper water supply system in terms of climate change, while the carbon dioxide emissions released during the production of a VPE system are almost the one tenth of traditional materials water supply systems. DOI: http://dx.doi.org/10.5755/j01.sace.13.4.12862