An all-in-one-package for greening facades: that is what the research project “50 green houses” offers. The greening prevents urban heat islands and improves the microclimate. In spring 2019 residents, owners and property managers in the district of Favoriten had the opportunity to apply online to receive a facade module. The first 50 prototypes of the newly developed Viennese green façade module “BeRTA” were being awarded for research purposes free of charge. In autum of 2019 the modules are being installed. Afterwards, BeRTA-modules can be purchased in all of Austria. In Vienna, a fund has been created to cover the costs of further module purchases. This is how a broad roll-out is made possible after the research project.

In Vienna and other cities various forms of planting greenery on buildings are already known. Nevertheless, there have not been any cost-effective, easily implementable all-in-one solutions for greening the road-side facade of existing real estate. This was the gap the project 50 green houses wanted to fill: in an interdisciplinary team and together with the city administration and other stakeholders, a comprehensive all-in-one solution was developed, which is now being tested in the Favoriten-district and will soon be available in all of Vienna and beyond!


According to climate forecasts, Vienna is expected to experience more heat during summer in the future – in some years there will be up to 100 days with temperatures above 30°C, which would be an increase of 550% compared to the average for the years 1981-2010. Green buildings or facades reduce the perceived temperature by up to 13°C and thus counteract “urban heat islands”. Especially along pavements and in ground floor zones, greening has a positive effect on the microclimate. Building greenery has many more advantages: it improves the air quality and ensures a more natural, healthier environment in the city.

All-in-one solution and process innovation

Until recently, no widely applicable, reasonably priced all-in-one solution for the implementation of green facades on existing buildings has existed. The “retrofitting” of existing facades was also hampered by lengthy processing and approval processes within building communities and the administration. On average, the necessary approval procedure of the City of Vienna usually took more than a year.

As part of the research project “50 green houses”, funded by the BMVIT (Federal Ministry for Transport, Innovation and Technology) in the “City of the Future” program, an integrated solution has been developed for the first time – in coordination with the City of Vienna – consisting of the “BeRTA Green Facade Module”, the innovative web-based participation instrument, as well as practice-oriented care concepts.

The BeRTA Green Facade Module

The BeRTA Green Facade Module is a simple, cost-effective, widely implementable plant trough solution for street-side facade greening. It consists of plant troughs, substrate (soil), climbing plants and trellises. What makes these troughs special is that all elements are coordinated with each other, developed specifically to work on existing buildings and contain all the components needed to green existing facades.

The relevant authorities of the municipality have been involved in the development of the module in order to contribute their professional input, thus making the future approval process transparent and rapid. The development has taken into account a variety of requirements, such as the use of durable and ecological materials or a suitable dimensioning that leaves enough space on the sidewalk. Site-specific plant selection and the development of suitable care concepts are also part of the project. The findings of about 100 interviews with owners and residents show the high demand for greenery in the city and have also been incorporated into the development of the Vienna Green Facade Modules.

Test run in Favoriten: free allocation of the first 50 modules

The innovation will be tested in 2019 in a co-creation process with 50 demo modules in the district of Favoriten – the target area of the innovation laboratory GrünStattGrau, in which the phenomenon of “urban heat islands” occurs particularly often.

In the spring of 2019, the prototypes for the Green Facade Modules were presented to the public. Owners and residents of the target area were invited to apply for the modules. As part of the research project 50 modules were then awarded free of charge to houses in the target area. The website guided interested parties step by step through the submission and asked applicants to submit all the necessary data in a simple way. The information provided helped the experts of the team of “50 Green Houses” to choose the individual module configuration for their respective location: Depending on the location and nature of the facades, suitable plants and, if necessary, a climbing aid are provided.

First implementation and broad roll-out

The 50 selected buildings from the district of Favoriten will receive a BeRTA green façade module, including delivery, installation and training, free of charge in autumn 2019. The first 50 green façade modules were assigned exclusively on the street side and placed in public space. The installation of the modules is carried out by specialists. The willingness to personally take care of the plants was judged to be particularly positive during the selection of the demo houses. Those committed to care receive a free enrolment by the team of “50 Green Houses”. The module is designed so that the ongoing care effort is limited: Thanks to the integrated water reservoir in the vessel, it must be watered only once or twice a week using a watering can or hose, even in hot weather. A professional pruning is recommended at least once a year. The costs for the ongoing care and maintenance are about 25 euros per month per module and are distributed between the residents through the operating costs of the building. Automated irrigation systems can be optionally requested as a chargeable option at submission. By means of monitoring, the measurable social and (vegetation) technical effects of greening of buildings in the target area of Favoriten are continuously surveyed and thus provide scientifically verifiable data for decision-makers, builders, planners and property developers.

Based on the findings from the project, a basic, multipliable business model is developed that can be transferred to other urban areas and cities. From autumn 2019, the BeRTA green facade modules are to be available all over Austria for a comparatively low costs. The city of Vienna has created a fund to cover the costs of another 100 green facades. Anyone who is interested can enrol in the projects’s mailing list.

Project partners

  • tatwort – Nachhaltige Projekte GmbH (lead management)
  • Muncipal Department 22 for Environmental Protection
  • Die Wiener Volkshochschulen GmbH – DIE UMWELTBERATUNG
  • GrünStattGrau – Forschungs- und Innovations GmbH
  • University of natural resources and life sciences (BOKU) – department of civil engineering and natural hazards, institute of soil bioengineering and landscape construction (IBLB)

The project is realised as part of the “City of the Future” program. “City of the Future” is a research and technology program of the federal ministry for transport, innovation and technology (BMVIT).


Mag. Susanne Lins, MAS, MSc

tatwort Nachhaltige Projekte GmbH

E-Mail: susanne.lins@tatwort.at

Website: www.50gh.at (in German)

This post is also available in: German