The objective of this work package is to develop the industrialised modular envelope system that carries and connects the main AEGIR technologies. WP4 translates the project concept into a practical renovation solution by bringing together façade elements, insulation, ventilation, automated windows, and renewable energy systems within one coordinated modular approach. 

The work centres on the development of an active envelope that can do more than provide a new outer skin. It is designed as a plug and play system that combines structure, insulation, ventilation ducts, photovoltaic and photovoltaic thermal technologies, window automation, and external cladding within a single façade concept. In this way, the envelope becomes both the architectural interface and the technical support for the wider AEGIR system. 

A major ambition of WP4 is adaptability. The system has been shaped through the needs of the four AEGIR demo sites in Spain, France, Denmark, and Romania, each of which brings different climatic, spatial, and architectural conditions. This has helped define a solution that can respond to local requirements while still relying on a shared modular logic and an industrialised method of production and installation. 

WP4 also explores how these technologies can be combined in different ways across the module family. Some panels remain relatively simple, while others integrate ventilation, active energy systems, and automated openings. This gives the system the flexibility to respond to different building types and renovation priorities without losing its consistency as a prefabricated solution. 

By the end of 2024, WP4 had established the main design requirements for the envelope system and advanced the final design of the modular solution. The next steps focus on prototype production, integration, and testing, helping to validate the AEGIR approach as a practical and replicable strategy for low-impact building renovation across Europe.