This paper presents a novel workflow for the design, robotic fabrication and assembly of lightweight timber structures based on a reciprocal frame structural principle. The described method expands existing research in the field by demonstrating a unified mesh-based workflow throughout the form-finding, manufacturing and assembly phases, as well as applications of augmented reality (AR) at several process stages. A case study in the design and construction of a prototypical self-supporting lightweight timber structure is presented. The process illustrates the dynamic transfer of data between various design, analysis and manufacturing simulation environments through the use of a common lightweight skeletal model and a just-in-time approach to manufacturing geometry creation. As such, the method serves as an example of Fabrication Information Modelling (FIM), an approach characterized by the synthesis of multiscale, interdisciplinary geometric representations, material properties, and fabrication parameters.