That was BauZ! 2023

Under the congress motto “Less. But let’s make more out of it!” and high above the roofs of Vienna …

Photo: © Enzberg

… in the TUtheSky room of the Plus-Energy Office High-Rise Building of the TU Vienna, the BauZ! Congress 2023 took place. It was already the 20th congress in this series.

We welcomed …

Tobias Waltjen, Foto: © Enzberg

Susanne Formanek, Foto: © Enzberg

a numerous and vivid audience …

Photo: © Enzberg

We opened with

Ronny Rantamäki, Foto: © Enzberg

  • Progress in the implementation of circular economy processes and tools in construction through the City of Helsinki’s Circular Economy Cluster and with
  • Progress in measuring thermal comfort under conditions where outdoor temperature and building occupants’ ability to intervene may be included as a framework.

    Susanne Formanek, Bernhard Lipp, Thomas Zelger, Foto: © Enzberg








We received opening remarks by our public sponsors an co-operation partners …

Theodor Zillner, Foto: © Enzberg

Michael Müller, Foto: © Enzberg

We continued with

  • Planning for a neighbourhood development at the Post-City Linz and with a
  • Participatory transformation plan for the energy supply of the Kahlenbergerdorf near Vienna.

from left: Doris Österreicher, Andreas Frey, Martina Majcen, Micha Schober, Katharina Franziska Schlager Photo: © Enzberg

This was followed by three development projects for the further integration of eco-data into BIM software:

  • BIM data for building greening
  • life-cycle information management of environmentally relevant product data, and a
  • Web tool for the automated creation of life cycle assessments of buildings based on a BIM model

Bente Knoll, Foto: © Enzberg

Ana Jugovic, Eva Bacher Foto: © Enzberg

On the second day of the congress, we were introduced to new constructions and materials:

Markus Winkler, Albert Treytl, Foto: © Enzberg

  • Model-predictive night ventilation supported by daylight-optimised shading in historic and listed buildings
  • Box window renovations with innovative glass products such as vacuum glazing
  • A cooling and heating ceiling with enhanced performance that temporarily stores condensation moisture in the material in cooling mode

    Ulrich Pont, Foto: © Enzberg

  • Foundations made of wood, also for multi-storey buildings, with examples from Dubai and Sweden
  • Mushroom mycelium as a new building material for insulation

from left: Karin Stieldorf, Zuzana Zavodski, Staffan Schartner, Maximilian Gruber, Jochen Käferhaus Photo: © Enzberg

This was followed by presentations on pioneering building projects:

  • The extension and adaptation of the primary and secondary school in Auersthal, Upper Austria.
  • The subtle renovation of a historic building with the same materials it was originally built of: stone, wood and clay: Hägi Wendl’s house in Vorarlberg.
  • The supply of a new multi-storey residential building with renewable heating and cooling under the boundary conditions of social housing in Vienna: Käthe Dorsch-Gasse 17
  • A new campus at the Hospital of the Sisters of Mercy Ried, Upper Austria.

Richard Hands (Moderation), Foto: © Enzberg

Andrea Dorsch, Christine Leitner, Foto: © Enzberg

Ulrike Schwantner, Dominik Abbrederis, Foto: © Enzberg

Tobias Ziegelmeyer, Foto: © Enzberg

This concise update by a congress plenary shortened to the two mornings was contrasted by a rich offer of six workshops to which the two afternoons were devoted:

Workshop 1. A project consortium with the participation of Eneergieagentur Steiermark and Danube University Krems invited to the “Kick-Off ReBUSk – From Status Quo to a Joint Strategy for Climate-Fit Professionals in the Building Sector”.

Photo: © Enzberg

Workshop 2: ADVANTAGE AUSTRIA with the Austrian Trade Delegate in Kijiv took the opportunitiy to present several stakeholders in the reconstruction of Ukraine: “Sustainable Reconstruction of Ukraine”.

Photo: © Enzberg

Susanne Formanek Photo: © Enzberg

Workshop 3: Led by GRÜNSTATTGRAU, the results of an understanding meeting with manufacturers of waterproofing materials and the City of Vienna (Ökokauf) were presented under the title “Sind wir noch ganz dicht? – Material ecology of roof sealing systems for green roofs” were presented.



Bernhard Lipp, Thomas Zelger Photo: © Enzberg

Workshop 4: As in 2021 and 2022, the FH Technikum Wien organised a three-hour workshop on the results of the Flucco plus project with the topics “Climate-neutral energy-flexible community” and “Dynamic comfort for energy-flexible plus-energy neighbourhoods (climate-neutral neighbourhoods)”.


Workshop 5: Just like in 2022, the innovation agency “RENOWAVE.AT” organised a workshop. This year the topic was: “Innovative system solutions for building renovation and heating exchange”.

Workshop 6: Also for the second time, the European H2020 project METABUILDING was represented with a workshop: “Innovation promotion and support of cross-sectoral cooperation projects of SMEs in the construction sector”.

Avoiding parallel runs of plenary events and workshops proved successful: both plenary and workshops were very well attended throughout.

Ronny Rantamäki, Ambassador Pirkko Hämäläinen, Tobias Waltjen, Werner Merzeder, © Embassy of Finland in Vienna

Already a nice tradition was the reception of the Embassy of Finland in Vienna, to which we were invited on Wednesday evening.

Herwig Bauer, Bernadette Krebs Photo: © Enzberg








For the success of our international event, the long-standing cooperation of the simultaneous interpreters Bernadette Krebs and Herwig Bauer was indispensable.



Doris Österreicher, Karin Stieldorf Photo: © Enzberg

The catering by the Gaumenfreundinnen added to the festive mood of the meeting. Photo: © Enzberg


As every year, the congress was a joint effort of the team at the IBO with the advisory board, from whose ranks also came the chair persons of the sessions, Susanne Formanek, Karin Stieldorf and Doris Österreicher. Special thanks to Richard Hands, architect in Glasgow, who chaired one of the sesssions!


Foto: © Enzberg

Foto: © Enzberg

We would like to thank for the generous funding by the Federal Ministry for Climate Protection (BMK), the support by TU Wien, Bau.Energie.Umweltcluster Niederösterreich, baubook GmbH, Business Finland as well as ADVANTAGE AUSTRIA.

Dr. Tobias Waltjen

Less. But let’s make more out of it. The dandelion can do it …

… man, in his own way, also. Photo: © Enzberg