How much upfront-embodied GHG emissions can wooden buildings save-displacement factors for wooden buildings

Wood can be a reasonable building material replacement for major greenhouse gas (GHG)-emission sources, such as concrete, steel, and masonry. Here, we conduct a detailed evaluation of the upfront-embodied GHG (UE-GHG) emissions benefits of wood compared with the other construction materials. By using lifecycle assessment (LCA) data from 92 case buildings in the literature, we provide an extensive synthesis of the displacement factor (DF) for wooden buildings. We use DF as a reference number for comparable building LCA studies to understand the GHG-emission benefits of wooden buildings. A pattern of lower UE-GHG emissions was found in our study; on average, the wooden buildings showed approximately 23% lower UE-GHG emissions than their non-wooden counterparts. Generally, low-rise (especially detached) buildings were found to have better DF values compared to mid-to-high-rise buildings. In addition, the process-specific LCA study found higher DF values for wooden buildings compared with input–output LCA studies that mostly base their calculations on average material manufacturing data. Finally, it is important to note that the DF values of different case buildings ranged from −0.15 to 0.69, which highlights the importance of careful technical considerations and efficient design of wooden buildings in order to maximize their DF benefits. We highlight the emergence of hybrid (structure) wooden buildings, especially for mid- to high-rise buildings, in recent years and emphasize the urgent need for a hybrid building definition because current practice allows the branding of low-wood-content buildings as wooden buildings.