To facilitate the necessary urban transformation toward a low-carbon future, the architecture, engineering, and construction (AEC) industry must evolve and embrace innovation in low-carbon construction systems. A three-pillar strategy centered on sustainability, digitization, and innovation can assist this risk-averse and traditionally unadventurous sector in adapting to a post-oil reality. In this context, the extraction of resources for construction materials, supply chains, and comprehensive lifecycle carbon assessments are being scrutinized. How can the AEC industry become more resource-efficient, minimize waste and excessive carbon emissions, and develop new models that promote mixed-use urban infill? Low-carbon prefabricated modular construction systems, particularly those utilizing engineered solid wood panel systems like load-bearing glue-laminated columns or cross-laminated timber (CLT) panels, alongside “design for disassembly” principles, present significant opportunities for reducing greenhouse gas emissions and avoiding construction waste, among other advantages. Such lightweight systems can store carbon in mass timber panels while promoting urban infill and densification. As mass timber construction has progressed from a niche product to a mainstream construction method, there is an urgent need for targeted research to address existing knowledge gaps and prevent duplication of international efforts. This chapter aims to identify and prioritize the future research agenda for mass timber by exploring the following question: What is the current state of knowledge, and where do research needs still exist in mass timber construction? For instance, many newcomers to mass timber often believe that fire performance, fire resistance, and sound transmission are critical areas for investigation; however, these topics have been extensively researched and are generally regarded as resolved. The focus has shifted toward answering new research questions, including explorations of embodied carbon, carbon storage, whole-life cycle analysis, durability, and the likely impact of innovative AI computer science on the design and structural calculation methods. There is already a growing research activity in mass timber, involving several research centers worldwide. Thus, defining trends and knowledge gaps will help avoid replicating research. A more nuanced discussion on knowledge gaps and industry research needs is timely to truly capture and disseminate information on the full potential of engineered mass timber systems as an innovative construction method, which helps reduce the use of carbon-intensive conventional building materials. To answer the abovementioned research questions, the author has consulted experts, and seven key research areas (RA) have been identified.