This paper presents a novel approach for the construction of nonstandard timber structures made from regionally sourced short dimensional lumber, which is enabled through human-robot collaborative assembly (HRCA). This approach is an attempt to address several challenges that exist in dominant timber frame construction practices, in particular: 1) Construction and manufacturing off-cuts that may not be used in the construction of full-height or full-span structural components, and 2) Short reclaimed lumber elements resulting from the deconstruction of buildings, which are limited (when not completely disposed) in their use for the construction of new structures. Therefore, to address these challenges, we ask the following research question: how can robotic assembly be integrated into a comprehensive design, planning, and construction process to facilitate the realization of building-scale structures made from short timber elements? To address the research question, three main research objectives are identified and experimentally explored: 1) Characterization of a comprehensive construction process, which consists of off-site HRCA of bespoke timber sub-assemblies, 2) Development of a suitable constructive system for robotic assembly, making feasible the realization of articulated structures out of short timber elements, and 3) Incorporation of these techniques and their constraints into an integrative digital design and fabrication method and implementation of a continuous digital design-to-fabrication workflow. These objectives are developed through simulation and physical experimentation (e.g., prototyping) and validated in a real-world case study, Robotically Fabricated Structure (RFS).