Retrofitting of building components using Building Information Modelling for sustainability

The use of energy-efficient and environmentally friendly materials and techniques is essential to mitigate climate change, especially for existing building structures, which contribute to carbon emission and increased energy demand. Retrofitting existing buildings is the most effective approach to meet sustainability goals. Building Information Modelling technology is used to implement green roofs in four existing structures. Carbon emission and following solar analyses for energy estimations were done with the help of standard tools: direct solar gains, monthly solar exposures, monthly heat gains, and comfort levels. The retrofitted building models were created with green roofs and material changes in walls and windows. Thermal transmittances (W/m(2)K) of green roofs, walls, and windows were compared between existing and retrofitted models. The core objective is to improve building energy efficiency and reduce carbon dioxide emissions by using a good mix of different passive design measures, provide energy-efficient solutions for the existing structures, and develop a building scale framework that can be followed to make existing structures energy efficient. Overall, retrofitting lowered the thermal transmittance of the roof, walls, and windows in all buildings. The retrofitted model enhanced the sustainability of all chosen buildings as indicated by the solar analyses and carbon dioxide emissions.