Building retrofit with multifunctional and prefabricated window
In most industrialized countries new buildings contribute only 10-20 % additional energy to the overall energy consumption whereas more than 80 % are represented by the existing building stock. Nevertheless the actual retrofit rate addressing the enhancement of energy efficiency is less than 1 % per year. Due to high investment costs, most present building renovations address single building parts as roofs, facades or heating systems only. This often results in not inter-coordinated and thus inefficient and finally expensive solutions, without an appropriate long-term reduction of energy demands. Prefabricated facade systems have a high potential to overcome the problems of traditional retrofit measures. With a suitable integration of building services into the prefabricated elements, an installation of the retrofit system from the outside of the building will be possible leading to minimized disturbances of tenants. The installation of the window including the sealing and connection with the rest of the facade and its insulation system is usually the most critical part of renovation work. Regarding this, a window prototype has been developed which already holds an insulation frame to cover the existing facade and a technical box providing additional functionalities like ventilation, energy delivery systems, renewable energy systems like solar thermal or PV and ICT components. Apart from integrating different technologies, the technical box can serve as the interface for the installations in the facade element and the installations inside the building. The whole window element is produced off-site and can be mounted into the existing window hole. For this, new business models including concepts for the whole process chain from planning to manufacturing, transport, mounting and commissioning are required. Especially for the mounting, a compromise between the usage of scaffolding, cranes and man power has to be identified.
Implementing sustainability - barriers and chances. Book of full papers