LCA-based strategic evaluation for building renovation construction projects

Abstract

It is well known that the existing building stock needs performance upgrades related to energy retrofit. In Italy and many European countries seismic structural safety standards requirements are also increasing, and therefore together with other renovation works, a structural rehabilitation is always needed. Structural rehabilitation is generally an invasive intervention on the structural sub-system, while energy redevelopment is less invasive as it is mostly performed in the building envelope, but it is economically relevant. Therefore, the high renovation costs and the limitation of the usability of the building during a renovation project often lead real estate developers to choose the easier strategy of complete demolition and reconstruction. This can be, perhaps, the easiest choice but, from an environmental and economic point of view, usually the least sustainable one. Environmental sustainability can be evaluated via the Life Cycle Assessment (LCA) approach, but LCA needs a complete evaluation of the existing and new building systems, sub-systems and components. Therefore, the strategic choice based upon LCA can usually be performed only late in the design process, when most of the technologic systems have been designed in detail. A parametric preliminary evaluation can help project managers and real estate developers to choose the most environmentally sustainable design alternative, even with a low level of knowledge of the existing building. The proposed approach uses a list of parametric costs for a building type to extract preliminary data about building quantities. Therefore, a mixed method that uses typical cost plans and existing LCA database is proposed to perform the preliminary LCA analysis of a building renovation project and evaluate sustainability.