The continuous development of the building envelope over the past hundred years can be exemplified by a few ground-breaking inventions. Firstly, the separation of primary and secondary structure during the beginning of the 20th century; by implementing a curtain wall façade to physically separate the façade from the building. This was followed by the development of double façades and a growing technologisation and use of the building envelope for building services and climate devices. Hereby the development of the ‘Polyvalent Wall’ by Mike Davies at the beginning of the 1980ies was a notable vision that formulated part of the building envelope as an active skin. The realisation of such a concept of a compact building envelope that encompasses all necessary supply units and building services in a very slender and integrated way has still not been accomplished. This vision has been followed by many technical developments; the latest being based on decentralised building services that are inseparably connected to the façade. But in spite of all these efforts, even forty years after Mike Davies‘ vision we are far from their realisation. Therefore, realising a ‘dynamic building envelope’ is a goal yet to be achieved. One technology to materialise this desire is Additive Manufacturing (AM): Layered production of parts from a 3D file. Over the past twenty years this technology has evolved from a support tool for product development into an independent production method. The term ‘AM Envelope’ (Additive Manufacturing Envelope) describes the transfer of this technology to the building envelope. Additive Fabrication is a building block that aids in developing the building envelope from a mere space enclosure to a dynamic building envelope. AM Envelope is an approach to this evolutionary step with the AM technology. This is exemplarily concretised and illustrated with building components for a post-beam façade, and then transferred to façade development over the next thirty years. This dissertation shows the potential of the additive methods for the development of façade construction: Additive methods change the way we design, build and produce building envelopes.