In this paper research on sustainable sourcing and innovative use of building materials is explored, through the prism of a complex case study of real building project. In particular, a novel use of sycamore as a structural material is investigated and reported. This includes methods and standards of its grading and classification, service classes and resistance to decay, in addition to results of its laboratory and in situ testing. A research method of longitudinal study is adopted, concentrating on the monitoring and assessment of its structural performance and conditions in which it might deteriorate. The study comprised of extensive desktop research on the sycamore properties, its standards and classification, followed by laboratory testing of its mechanical properties, namely bending strength and compression parallel to grain. In addition, an experimental build with half sycamore-half softwood structural timber frame was designed and constructed and early monitoring and assessment results reported. Finally, the in situ testing on the main building was undertaken, including visual observations, measurements of moisture content and wood decay detection. The latter was undertaken using digital micro probe to identify potential soft wood and cavities in sycamore and determine the extent of problems. So far research has established that sycamore can be applied to the structural and constructional aspects of building design and assembly, as long as due attention is paid to its detailing and resistance to decay and insect attack, moisture control, ventilation provision and service class uses. However, it has to be noted that the research findings of this project cannot be statistically extrapolated to a broader geographical extents, due to the locality of sycamore sourcing limited to within the site boundaries.