Almost 40% of energy consumption in Germany is used in the building sector. The largest part of the building stock was built between 1949 and 1979 and performs the worst in terms of energy efficiency. Our research project seeks to discover how as many requirements as possible can be incorporated into a functionally expanded prefabricated window element for use in the energy-saving renovation works of post-war buildings. The installation of conventional window replacements is complicated by the involvement of many trades and numerous interfaces at geometrically and structurally challenging places. Through the integration of sun, glare and insect protection in an elegant, prefabricated, quality element – the “window machine” – residents should profit from a less intrusive construction process, lower capital costs as well as higher energy efficiency. Alongside typical window functionality, the inclusion of building services such as ventilation / heat exchanger, electrification / building automation were studied as additional components in the window element. The many potential solutions identified at the start of the project were further investigated according to the following parameters: Design quality, modular construction, simplified construction process, maintenance and dismantling, reduction of interfaces and associated trades, integration of functions, degree of tolerance, connection to surrounding building elements, daylight, sun protection, insect protection, heat protection and isothermal characteristics. The advantages and disadvantages of each construction were compared and analyzed. Proposals were developed over several selection rounds resulting in three prototype case studies. Meanwhile, three proposals for integrated ventilation were chosen and assigned to the prototypes. In accordance with idea of prefabrication, the window is conceived as an inte¬gral component of the element. Following the same principles as a car production series, the form is governed by the installation of the maximum range of features, with individual components incorporated as desired in a given project. The simplification and speeding up of the construction process requires a precise building survey and more in-depth planning. Thus, the focus of effort shifts from the construction itself to the planning and production processes. Prefabrication offers new possibilities in the reduction of different materials and their correct separation for recycling (recyclability). The economic and energy efficiency of the window module is a function of the technologies integrated: The greater the number of services accommodated in the window element, the more worthwhile the additional expense as compared to a conventional window replacement. In addition, energy savings are achieved through the thermal insulation and heat recovery from the ventilation system     «

Almost 40% of energy consumption in Germany is used in the building sector. The largest part of the building stock was built between 1949 and 1979 and performs the worst in terms of energy efficiency. Our research project seeks to discover how as many requirements as possible can be incorporated into a functionally expanded prefabricated window element for use in the energy-saving renovation works of post-war buildings. The installation of conventional window replacements is complicated by...     »