VS-A develops façades and lightweight coverings forming building’s envelopes. Setup in 1989, we are today 3 offices based in France, Hong Kong and South Korea, 40 architects and engineers, among which 12 partners, over 400 built projects, mainly, but not only, in Europe and Asia. Envelope is the point at which many architectural ambitions coalesce, but it is also subject to regulatory and economic constraints and has to meet increasing demands in terms of performance. These generally relate to comfort, energy and safety. The previous facade engineer has become today an archi-technical designer, specialised in building physics and parametric design. Bridging the gap between architectural and technical considerations enables to generate bespoke details consistent with architectural concepts and sometimes vice-versa. Such developments involve much to-ing and fro-ing and cooperation between all stakeholders, including the client. This can involve current products, sometimes slightly diverted from their original function, or the development of specific customized products using appropriate digital modelling tools or scale models, and requiring thorough performance testing. We aim to develop unique and coherent stories on each project, specific to its geographic location, either small or large scale, either low- or high-tech.