MA 22
Jürgen Preiss
Green façade for heat wave buffering on a public administration building in Vienna
Solution complète
Green façade of the administration department for waste management (MA 48) at Einsiedlergasse 1, Vienna c MA 22
Climate change can cause heat islands in cities, affecting public health and infrastructure. Vienna thus developed a pioneer program for greening buildings, including the façade of the department for waste management, to investigate the effects on heat flow in winter and the influence on the heat transfer losses and heat demand of the building. The facades were also to create ecological niches for insects and birds and positively affect the surrounding indoor and outdoor climates.
Dernière modification 09 Mar 2021
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Contexte
Challenges addressed
Façade-related vertical greenings respond to urban challenges associated with climate change, such as the heat island effect, and loss of biodiversity. However, they can entail high costs for construction and maintenance and require high technical know-how. Using rainwater for irrigation is a technical challenge for the irrigation and nutrient supply. Finally, monitoring impacts on biodiversity and particularly insects challenging given the difficult accessibility of the vertical wall.
Emplacement
Einsiedlergasse 2, Vienna, Austria
North Europe
Traiter
Summary of the process
Successful implementation of the project required the participation and collaboration of a wide scope of individuals throughout all project phases. A public and private partnership approach enabled public administrations to share the tasks and risks of planning, realization and operation together with private partners (building block 2). The collective effort of experts from different fields further facilitate the creation of an instructional guideline (building block 1) with technical information for architects, planners, developers, public institutions, and interested citizens. This guideline further serves as a decision-making aid when choosing the ideal type of greenery for different facades.
Building Blocks
Instructional guideline for supporting façade greening
The guideline for façade greening was prepared by the Austrian Association for Building Construction and by the University for Soil Culture on behalf of ÖkoKauf Wien, the program for the ecological procurement of the city of Vienna. The guide was presented in February 2013 within the framework of a conference in the Vienna University of Technology. It offers valuable specialist information to architects, planners, developers, public institutions, as well as interested citizens and serves as a decision-making aid when choosing the ideal type of greenery for different facades. Contents include general information (e.g. target groups, scope, definitions, advantages of a green façade), as well as information on various facade greening systems, their ecological and technical functions and design possibilities. A system overview, funding options and a checklist serve to help users prepare and plan façade greening by examining the necessary conditions and prerequisites. Finally, the guideline highlights best practice examples from the Vienna area and further references to literature and regulations.
Enabling factors
It was necessary to draw on the various facets of appropriate knowledge to develop the guide, including e.g. engineers and an association for greening buildings. Financial resources for the content creation, print and publication were planned in the annual project budget from the environmental department – MA22. There were no additional funds. The drafting of the guide was politically desired and was integrated into the political program.
Lesson learned
There was a high demand for the guide - the first edition (3000 copies) was already out of print within the first year after publication. A new edition will be published in early 2017, which will be complemented with additional shorter information brochures (folders, leaflets, etc.).
Resources
Sharing risk/responsibility in a Public Private Partnership
Public Private Partnerships (PPP) enable public administrations to share the tasks and risks of planning, realization and operation together with private partners in joint projects. Accordingly, the Hernals District Development Commission decided to promote the façade greening measure in the framework of "Public Private Partnership" models. With the expertise of the Viennese Environmental Protection Department - MA 22 - and the support of the district as well as the local area, a remarkable green oasis was created in the form of a green façade at a private house in the Ortliebgasse. The collaboration has proved equally valuable for the project and the public and private partners involved.
Enabling factors
The most important success factor was the cooperation of the actors. The costs for the planning and construction were shared by the district and the environmental department MA 22 and the private owner, who is responsible for the maintenance. The agreement was based on an informal contract between the private owner and the district.
Lesson learned
The fulfillment of public tasks is traditionally assigned to public administrations, making it challenging to break from this historically ingrained model. The diverse requirements of modern societies however, show that a strict separation between the public and private sectors is no longer feasible. New approaches such as Public Private Partnerships (PPP) show that it is quite advantageous for selected projects to share the tasks and risks of planning, realization and operation together with private partners. While offering many benefits, it should be noted that the planning and administrative efforts of coordinating a PPP are relatively high. These can, however, be simplified with experience and even save costs and resources in the longer term.
Impacts
In total, 850 square meters of façade were mounted, totaling 2.850 meters with about 17.000 plants (mainly perennials, grasses and herbs) and increasing the amenity values of the area for the surrounding community. As a pilot project, the greening of the building façade served primarily to advance the state of knowledge on the potential effects of such an EbA measure. Within the framework of this research project (2016, TU Wien, Korjenic on behalf of MA 22), the green façade and its monitoring serve as the first step towards clear definitions of the effects of façade greening on heat demand. The green part of the wall has also improved thermal insulation by 21% (see figure 2) and led to a change in the annual transmission losses of 54.7 kWh to 45.1 kWh per square meter of green exterior wall. While impacts on biodiversity and habitat functioning still require further survey and research work, effects are estimated to be positive. There has also been a strong increase in levels of awareness of this topic amongst planners, residents and developers.
Beneficiaries
Citizens enjoy improved climate regulation, air quality and aesthetic values, while employees have cooler indoor temperatures in summer. The knowledge and experiences generated benefit diverse stakeholders and enable wider façade greening.
Sustainable Development Goals
SDG 3 – Good health and well-being
SDG 11 – Sustainable cities and communities
Story
The Vienna environmental department - MA 22 has been dealing with the topic "heat in the city" for more than 15 years, including the preparation of a climate assessment and map based on thermal images and the implementation of measures, such as green space networking, roof greening, façade greening and rain water management. This measure includes both the ground-based, non-irrigated building greening and the facade-related, irrigated variant as two-dimensional systems or with planters on the façade (“living-walls”). In designing such an EbA solution, it is important to consider the holistic aspect by valuing all co-benefits, such as heat insulation, air purification, improving of the biodiversity, improving the urban design, the human well-being and quality of stay, noise reduction (especially reduction of echoes, eg in courtyards), protection and upgrading of the building substance and the positive influence on photovoltaic systems. Also, the façade greening program particularly depends on political willingness. Finally, the implementation process is very complex and it has been shown that successful cooperation requires several actors and the cooperation of experts from various disciplines. In order to promote facade greening, in 2016 a project was launched by the City of Vienna with experts from all relevant interdisciplinary disciplines working on defining legal requirements and framework conditions, ecological, economic and social sustainability, best practices, quality assurance procedures, and implementation instruments. The clarification of fire protection relevant questions are already finished and the new guideline for facade greening will approximately be published in early 2017.
