Despite the significant environmental impact of the building sector, sustainable building practices are yet to be widely adopted. This paper describes a practical approach based on computational design and additive manufacturing (AM) to generate modular and structural walls, following design for disassembly and recyclability principles. In this research, the anisotropy of recyclable short-fibre reinforced thermoplastic (SFRTP) composites is utilised. The proposed methodology involves starting from the building’s typology and using topology optimisation (TO) as a form-finding tool in the design of structural wall modules. The finite element analyses (FEA) guiding the TO are based on conventional building-codes used for load calculations. The TO-defined modules are then further optimised in stiffness by matching the principal stress directions with the AM printing path. Two case studies, the ground floor of a 3-storey building and a bus shelter, are used to illustrate the outcome of the approach. This comprehensive workflow generates structural elements with built-in optimised and tailored performance while enabling unique geometries that combine structural efficiency with architectural creativity.