Key Parameters Featuring BIM-LCA Integration in Buildings : a Practical Review of the Current Trends

The construction sector is responsible for 40% of carbon emissions, 14% of water consumption and 60% of waste production in the world, generating a state of unsustainability. In order to keep these values under control and make the most sustainable choices starting from the earliest stages of building design, a Life Cycle Assessment (LCA) can be used. This consists of an analysis of the environmental impacts of a product, activity or process throughout all phases of the life cycle. The fundamental problem of implementing this analysis process in the construction sector is the difficulty in managing the fragmented building information that covers all aspects of buildings life stages in an integrated way. The Building Information Modeling (BIM) approach offers the possibility of managing a complex information system in an integrated manner. The BIM-LCA integration solutions proposed in recent years made LCA analysis faster, cheaper and usable by more professionals. This paper proposes an analysis of the state of the art of the research published in the last ten years regarding the integration of BIM-LCA as a methodology whereby the BIM approach can support and simplify data management for LCA analysis. The aim was to present the work methodologies tested so far and to describe all the factors that were considered in applying the BIM-LCA integration. The novelty of this review consists of identifying a series of more recurrent parameters and measures used by most researchers deriving a trend of possible and consolidated workflows. The result is, therefore, to present evidence of a general heterogenous framework and to define the common and widespread approaches identifying the main features

Consistent BIM-led LCA during the entire building design process

Life Cycle Assessment (LCA) is a suitable method to analyse the environmental impact of buildings' design choices. However, the nature of the building design process leads to a dilemma when applying LCA in early phases. LCA can be fully performed only in the later design phases when complete information is available, but it is too costly to make changes. As a result, LCA is scarcely employed as a decision-making tool. Building Information Modelling (BIM) can assist LCA during the design process. So far, two different approaches are usually adopted to perform the BIM-based LCA of buildings. The first approach concerns performing LCA with a detailed BIM at the end of the building design process. The second approach involves simplified methodologies for early design stages with uncertain data. This study proposes a novel approach for applying a consistent BIM-led LCA from the early design stages to the detailed ones based on lower to higher level of accuracy. Since the BIM elements are specified with increasing level of detail in each design phase, the method uses different LCA databases for the Level of Developments (LODs) of the building elements. Accordingly, LCA calculations are based on mixing the databases in every design phase. This is possible as long as the databases use identical background data. The framework helps to provide consistent information for decision-making throughout the whole design process, both in the later design phases and early ones with a simplified BIM.ISSN:1755131