The building and construction industry is one of the largest greenhouse gas producers, accounting for 39% of global emissions, most of these coming from concrete and steel. Mass timber construction (MTC) potentially offers a sustainable alternative to these traditional building materials. However, more research is needed to establish the sustainability credentials of MTC relative to traditional concrete and steel structures, especially for mid-rise structures. The aim of this study is to evaluate the environmental and cost performance of mid-rise mass timber buildings by conducting a life cycle assessment (LCA). The LCA uses a cradle-to-cradle approach, considering the global warming potential (GWP), freshwater use (FW), and total use of non-renewable primary energy resources (PENRT). Results indicated that mid-rise mass timber buildings have significantly lower impacts than concrete buildings, with their GWP approximately 30 times lower, FW about 20 times lower, and PENRT reaching a negative value. Additionally, the cost analysis revealed that MTC buildings can be cheaper to build and thus possibly more profitable than concrete buildings. These findings establish mass timber as a viable and sustainable option for the future of Australia’s construction industry.