Comparative whole building LCAs: How far are our expectations from the documented evidence?

Buildings are responsible for a considerable portion of the embodied and operational CO2 emitted by human activities. Some building attributes have taken on the mantle of environmentally preferable. Through a systematic literature review, this paper investigates if the literature on whole building Life Cycle Assessments (LCA) confirms some environmental assumptions that are perceived as always truthful, e.g. (i) wood is better than concrete and steel, (ii) renovation is preferable to demolishing and building anew, and (iii) operational loads are more intensive than embodied loads. The search also allowed to trace if advanced methodological modelling in LCA brings new insights into the mentioned perceptions. The assessment of over 250 case studies pointed that LCAs applied to complex systems, such as a building, embed crucial issues to be modeled, and rules of thumb lose veracity. Furthermore, as LCA incorporates deepened mathematical models, outcomes become less predictable, and paradigms should be interpreted with care.