The scope of this project was to design a new two-storey building, a timber-framed dwelling on the existing garage building. The design works include an assessment of the strength and capacity of the existing building, such as the capacity of the concrete slab. The project required careful integration of new and existing systems, with steel beams introduced to create a new load path and support the upper-level structure. The design included all primary structural elements such as ridge beams, lintels, studs, and wall bracing, ensuring the new dwelling performs under wind and seismic actions. A comprehensive review of the existing concrete slab, beams, and portal frames was undertaken, with strengthening measures incorporated where required. The final solution provides a coordinated and efficient structural system that enables vertical expansion while ensuring the overall building performs reliably under the increased demands.