The building sector has revealed a need for process optimization, mirrored by the ongoing discussion around industry 4.0 and increasing automation in building design and construction. Within this context, the prefabrication and standardization of building elements provide interesting opportunities for optimizing the construction process. Off-site fabrication of building envelope and systems can provide significant advantages in terms of process, quality and safety management. This paper presents an outline of state-of-the-art building opaque envelope prefabrication, with particular focus on timber building skins, through a collection of best practices both in the field of building retrofit and new construction. This research is the result of shared research interests and synergies among the Institute for Renewable Energy at Eurac Research and the Innovation in Applied Design (IAD) Lab at the University of Sydney. Results highlight current limitations of envelope prefabrication and outline development opportunities both at technical and production process level. These findings and the conclusions we draw from them will set the foundations for expanding the adoption of an industrialized fabrication approach in the construction environment.