The life cycle carbon footprint of refurbished and new buildings - A systematic review of case studies

CO2 is emitted throughout the lifespan of buildings-from construction through to operation, and eventually, demolition. Life Cycle Carbon Footprint calculations (LCCF) can be employed to provide useful evaluation metrics for the analysis and comparison of their environmental impact. This paper brings together, for the first time, a systematic review of the LCCF of 251 case study buildings from 19 different countries. This review focuses on the comparison of the LCCF of refurbished and newly constructed buildings, through the synthesis of the overall outcomes of these studies, to identify whether refurbishment or replacement design alternatives achieve better performance. The results highlight that the average embodied, operational-related and demolition-related CO2 is responsible for 24%, 75% and 1%, respectively, of LCCF. Furthermore, this review indicates that while the type of heating and energy supply system can significantly impact overall LCCF (when normalised to kgCO(2)/60 years/m(2) floor area), other factors, such as building floor area or number of storeys, have minimal effect. A comparison between the LCCF of refurbished and new buildings showed that while most refurbishments had lower LCCF than most new buildings, some new buildings performed better than refurbished ones. Thus, findings suggest that on the basis of current evidence, it is still not possible to conclusively determine which of the alternatives is preferred. Finally, the paper highlights the current state of buildings LCCF, in particular in terms of the analysis scope and limitations, illustrating how these terms were interpreted differently in the examined case studies, and subsequently highlighting the need for a unified protocol to be developed for building LCCF analysis.