Collaboration Models for Industrialised Renovation Methods and Prefabrication – Experiences and Outlook on Organizational and Legal Frame Conditions

Today building renovation in Europe is characterized mainly by on-site processes, which may be inefficient with regard to cost and time. The E2ReBuild project aimed to further develop, investigate, evaluate and promote new cost-effective and energy efficient retrofit strategies. Within the seven Demo projects, innovative industrialised renovation methods and prefabricated façade and roof elements were developed and implemented. The evaluation of their realization process provided feedback from practice, identified dependencies and causal motives and showed needs for future actions of policy makers and stakeholders.A key aspect for successful renovation within the E2ReBuild demonstrations was the quality of the applied collaboration model. Appropriate team set up, coordination in early planning stages and joint development guaranteed optimization and a smooth workflow for renovation. Further the choice of the Design-Bid-Build or Design-Build approach influenced the collaboration on how responsibilities and risks were handled and thus the contractual situation among owners, planners and contractors.However, neither the Design-Build nor the Design-Bid-Build approach could sufficiently meet the requirements of an optimized team set up. Within both approaches stakeholders struggled with uncoordinated actions, misunderstandings, lack of knowledge-sharing within the team and the interface between planning and construction. A lot of know-how got lost due to changed actors or the missing know-how of relevant actors (e.g.: the timber element manufacturer) in early planning stages.However, current procurement legislation hinders early collaboration and appropriate team set up. In future, actions within legislation and changes of traditional renovation routines are necessary. Procurement legislation should enable teams to offer their services for planning and construction together or to integrate relevant know-how in early planning stages. In future, the influence of appropriate team set up and communication as driving forces for joint development and optimization regarding quality, costs and time have to be recognized. Finally, all interviewed stakeholders within E2ReBuild stated a high replication potential of the applied technologies, processes and models – provided that framework conditions would facilitate their implementation.