Ergebnisbericht zum Branchenprojekt Prefab.Facade - Performancesteigerung von kreislauffähigen, seriell vorgefertigten Fassadenelementen

The construction sector is responsible for a significant share of global resource consumption, CO₂ emissions, and waste. Approximately 34 % of global CO₂ emissions and 32 % of energy consumption are attributable to the construction and operation of buildings. In particular, existing buildings with poor energy performance offer substantial potential to reduce energy demand through renovation. At the same time, integrating resource‑efficient and circular construction methods, combined with automated manufacturing, can lower raw material use and environmental impacts while creating new economic opportunities for the construction industry. The research project “Prefab.Facade – Performance enhancement of circular, serially prefabricated façade elements” aimed to establish the basis for developing and broadly deploying modular timber frame systems for renovation, manufactured in an off‑site prefabrication process. The focus was on maximizing the degree of prefabrication, implementing an end‑to‑end digital process chain from planning through fabrication to installation, and optimizing the systems ecologically and economically. The project investigated innovative approaches to façade renovation, including digital as‑built surveying using laser scanning and drone photogrammetry, the development of optimized layer assemblies, and the automation of manufacturing with industrial robots. Two full‑scale (1 : 1) experimental walls built in the laboratory enabled practical testing—for example, the installation of façade elements, the evaluation of mounting systems and efficient inter‑module connection techniques. In addition, the minimization of thermal bridges, seamless ventilated render façades, and various cladding systems were assessed for practical suitability. The results show that modular façade systems can achieve significantly higher circularity and lower environmental impacts than conventional external thermal insulation composite systems (ETICS). Serial prefabrication shortens construction times, reduces labor requirements, minimizes weather‑dependent work, and improves execution quality. The digital process chain and precise as‑built data enable efficient planning and implementation, while targeted material choices substantially reduce environmental impacts. Overall, the investigations provide baluable insights for optimizing construction processes and advancing sustainable, resource-efficient facade systems that cam make a decisive contribution to promoting circularity and climate neutrality in the built environment.