MAFa is a pre-fabricated, multifunctional panellised façade, which incorporates ventilation with heat recovery, Passive house windows and Photovoltaics (PV). Hereby, the Passive house standard can be met by retrofitting and the construction time can be reduced to 1-2 days per dwelling. The technological innovation is the smart supply of the decentralised ventilation system by PV modules and of an auxiliary battery system serving as back up together with an energy management system. Specific challenges are the demonstration MAFa within the context of social housing; however, there is a replication potential at Wiener Wohnen and other housing companies.
Contents and Objectives
The aim of the thermal retrofitting of a residential building with 33 domestic and 2 commercial dwellings, owned by the municipality of Vienna, located on Hütteldorfer Straße 252 in the 14th Viennese district, is to achieve „Nearly-Zero-Energy standard". In order to achieve this goal, an innovative „Multi-Active Facade" is developed, which consists of a prefabricated wooden pillar beam system with a special cardboard-honeycomb insulation (by gap-solution GmbH) and built-in building equipment. The façade layer serves for two purposes mounted to the existing outer walls, which forms the passive house envelope and at the same time includes all building appliances needed for passive house standard. These appliances are supplied by PV modules integrated in the facade, being the novel part of the „Multi-Active Facade". The PV-modules are connected to a battery system acting as a back up within the overall energy management system.
For renewal solutions towards energy-plus standard a ventilation system is an essential element to reach the passive house standard. Within the optimized energy efficiency concept are decentralised ventilation units foreseen. The components of the ventilation systems are driven with direct currency in order to ensure a high level of efficiency with low power consumption (approx. 5-10 watts/device). The innovative part of the project is to produce solar electricity as part of the multi-active façade. For those time intervals, in which no sun is shining, a battery storage will take over the necessary supply.
The multi-active facade MAFa is also part of a larger Smart City project EU GUGLE, which is dealing with ambitious nearly zero energy renovations in the districts Penzing and Rudolfsheim-Fünfhaus of Vienna. This will be done in close cooperation with the city of Vienna and includes co-financing, which go beyond the multi-active facade towards other innovative deep renovations in buildings in the two districts. The multi-active facade MAFa is the most innovative project under the EU GUGLE building renovations and combines the requests of short construction times of the building users and high efficiency due to their special design. The scientific evaluation of the project results (design adaptations, socio-economic analysis and representation of the measured values of a test sample) has been performed by the coordinator BOKU in close cooperation with the project partners. Energy-related potentials and other added values of pending renovation objects of Wiener Wohnen are investigated in the framework of a master thesis at BOKU3. From the demonstration and implementation of an ambitious renovation in social living area in Vienna replication effects are derived. Of the analysed 196 apartment houses, 41 or 21% are classified as suitable for MAFa, while all other objects are assigned to be renovated with conventional ETICS.
Prospects / Suggestions for future research
Nearly-Zero-Energy objects combined with renewable key technologies are assigned to form an energetically balanced symbiosis. Together with pre-fabrication it reduces the manufacturing costs and allows an effective replication. Future plus energy houses with pre-fabricated facades may serve as highly efficient multi CO2 sinks. Results of this research project – so it will be accepted by the market – lead to sustainable dynamics for the expansion and technological leadership of the cooperating companies. Nationally and internationally, innovative systems and methods for building and property assessments could be continuously further developed. Increasing awareness of a holistic, integral and sustainable construction will reinforce the trend toward sustainable buildings. This is reflected in the market value of the property of Hütteldorfer Straße 252. Currently, low energy characteristics of buildings have only little but though positive impact on the value of the property. It is assumed, that this impact will increase, if more observations are available.
Universität für Bodenkultur Wien, Department für Bautechnik und Naturgefahren, Institut für konstruktiven Ingenieurbau, Arbeitsgruppe Ressourcenorientiertes Bauen