GreEnergieausweis AT - Ways of integrating greenery into the Austrian Energy Certificate
The increase in heat days, especially in urban areas, affects the health of residents and reduces the quality of life. Greening buildings can help to reduce the negative effects of overheating.
At present, there are no widely known and proven methods for demonstrating the effects of greening measures on the energy efficiency of buildings. The Austrian Energy Performance Certificate enables the comparability of the energy efficiency of buildings. It is the basic calculation method for the verification of the energy performance requirements according to OIB guideline 6 for new buildings and the renovation of buildings. Building-integrated greening measures and their effects are currently not taken into account in the calculation methods of the energy performance certificate. Therefore, the question arises how the integration of roof greening and facade greening measures into the currently existing calculation methods can be realised.
In order to identify the possibilities for integrating building greening into the energy performance certificate, the national and international initial situation was examined in advance and the acceptance of relevant stakeholders in this area was surveyed. Based on these results, possible adaptations of calculation models were identified in order to illustrate greening building measures in the energy performance certificate. The need for continued action was conclusively part of the investigations.
The examination of the current situation on the basis of national projects, standards and consultations with international experts has shown that the integration of building greening into the energy performance certificate is an issue. At the moment, however, there are largely no approaches towards implementation. The results of an online survey with participants from different fields of activity such as planning, research, authorities, software producers, etc. as well as personal interviews with other relevant stakeholders have shown that the acceptance for the integration of greening measures in the Austrian energy performance certificate is generally high. These positive attitudes were also shared by the participants in an online workshop.
Different standards, which allow adaptations for the integration of greening elements in their calculation methods, were analysed in more detail. In this way, the possibilities for the implementation of building-integrated greening in the energy performance certificate calculation could be identified. For example, ÖNORM EN ISO 6946, the standard for U-value calculation, offers the possibility of taking into account the increased thermal resistance of green facades. In ÖNORM B 8110-6, the standard for calculating heating and cooling demand, the effects of greening elements on the cooling demand of non-residential buildings can be taken into account by additional shading factors or energy transmission coefficients. This possibility for adaptation is also offered in ÖNORM B 8110-3 for the calculation of summer overheating. In ÖNORM B 8110-5, synthetic climate data sets of a future climate period as well as models of the microclimate (urban heat island effect) could be considered with regard to the calculation of the cooling demand as well as for the verification of summer overheating.
There is still a need for further research and development for actual implementation. For example, the development of standardized test procedures for characteristic values of building-integrated greening systems is necessary to be able to use reliable data in the calculations.
Schöberl & Pöll GmbH
Project or cooperation partners
- GRÜNSTATTGRAU Forschungs- und Innovations GmbH
- University of Natural Resources and Life Sciences, IBLB Institute of Soil Bioengineering and landscape Construction