Computational bim for green retrofitting of the existing building envelope

Abstract

Green retrofit is crucial to turning existing buildings into green buildings, but its design and analysis process is dependent on numerous disjointed methods. Various decisions are required to optimise the building efficiency, such as the choices of building materials, opening sizes, and glazing types. Therefore, this study explores the application of computational building information modelling (BIM) to automate the process of design decision-making for green retrofitting of the existing building envelope. A BIM tool (Revit), a visual programming tool (Dynamo) and multi-objective optimisation algorithm were integrated to create a computational BIM-based method for building envelope retrofitting by optimising overall thermal transfer value (OTTV) and construction investment cost. The proposed model was validated through a case study; the results showed that the optimised design achieved 44.78% reduction in OTTV with investment costs of RM (Malaysian ringgit) 369,182. The newly formulated computational BIM-based approach can improve the level of automation in green retrofitting design decision-making.