The building sector accounts for around 40% of global greenhouse gas (GHG) emissions and is a major driver of resource consumption and land sealing. A paradigm shift in the way we deal with the existing building stock is therefore indispensable. While research and practice have so far focused primarily on resource efficiency, densification or the technical retrofitting of existing buildings, the project Counterintuitive Building Types (CBT) directs attention to a largely unexplored segment: suburban retail and commercial properties developed since the 1970s. These rationally planned, mostly monofunctional buildings are often regarded as demolition candidates. The project's central research question, however, asks whether and how these purpose-built commercial structures can be understood as a resource for sustainable transformation. Initially counterintuitive strategies such as adaptive reuse, densification, or the integration of social programs can represent viable alternatives to demolition and new construction.

In Austria, there are beyond 13 million square meters of retail space in stationary commerce, a significant share of it located in suburban areas. These buildings are characterized by automobile accessibility, large-scale parking infrastructure and functional mono-programming – access / consumption / departure. Structural changes in retail, the rise of digital sales platforms and pandemic-related declines in footfall have left many of these sites underused or threatened by vacancy. Prevailing practice still considers demolition and replacement the standard solution – despite the high ecological costs and even though these properties already contain substantial resources such as load-bearing structures, transport connections and existing infrastructure. It is precisely in these existing conditions that CBT identifies their potential for a resource-conscious and climate-neutral urban development.

Against this background, CBT demonstrates that a future-oriented transformation of such buildings is indeed possible. At the core of the project were four real sites, each investigated through seven scenarios – ranging from demolition/recycling and re-greening to retrofit strategies, adaptive reuse approaches and more complex extension and densification models. The aim was both to develop concrete transformation strategies and to provide tools for systematic decision-making. These include a catalogue of architectural elements used for adaptation and conversion, as well as a tabular scenario matrix. Building on this structure, a complementary consequences matrix was developed, making technical, economic, social and ecological implications comparable across scenarios.

The methodological approach was interdisciplinary. The Institute of Spatial Planning, Environmental Planning and Land Rearrangement developed indicator models and location analyses that served as the basis for ranking the sites. The real estate partner WMV contributed market valuations, costbenefit analyses and market studies. The Institute of Structural Design investigated the existing building substance, load-bearing capacities and possibilities for structural adaptation, while the Working Group on Sustainable Construction evaluated the scenarios using life cycle assessments and GHG accounting. As the architectural basis for these investigations, master's theses, doctoral workshops and a graduate design studio at Graz University of Technology developed architectural scenarios and typological analyses that explored how commercial building stock could be transformed through design-driven approaches.

Creativity, empathy and architectural design expertise proved equally fundamental throughout the process. Transforming ordinary purpose-built structures into attractive and multifunctional spaces requires architectural imagination and advanced representational skills – particularly when reconsidering the relationship between interior and exterior spaces, including the often entirely neglected design of open spaces and landscapes. All subsequent analytical work within the project was based on these architectural design investigations. The resulting proposals were translated into 3D models, performance indicators and graphical representations to facilitate continuous interdisciplinary discussion and coordination within the consortium.

The project demonstrates that even seemingly banal commercial structures contain considerable transformative potential. From an ecological perspective, reusing existing structures and infrastructures can save significant amounts of GHG emissions. Economically, renovation and adaptive reuse often prove more viable in the long term than demolition and replacement. Socially, counterintuitive programs – such as education, culture or collective living – can transform monofunctional retail sites into new meeting places and "third places" for suburban communities.

The results, presented comparatively through the project scenarios, underline that suburban commercial properties are not a marginal phenomenon but a central issue for both spatial planning and urban development. Their transformation creates opportunities not only for resource conservation, but also for generating new social and cultural qualities. At the same time, the project demonstrates that the tools developed within CBT are transferable beyond the investigated sites and can serve as planning and decision-making instruments at the municipal scale. Future research should further explore the integration of these instruments into legal and political frameworks, address questions of governance and funding, and connect these approaches with broader European debates on the decarbonization of the building stock. The project ultimately demonstrates that the climate-neutral city of tomorrow will not primarily emerge through innovative construction, but through the continued transformation and re-imagination of the existing built environment.

The project was carried out within the framework of the program line "City of Tomorrow" of the Austrian Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation, and Technology (BMK) and the Climate and Energy Fund. With its results, it contributes to the strategic goals of the program: building a sustainable energy system, reducing climate impacts, increasing competitiveness and strengthening the quality of research and development in the field of climateneutral cities.

Project management

Assoc. Prof. Dr. Andreas Lechner, Graz University of Technology - Institute for Building Science

Project or cooperation partners

• Graz University of Technology - Institute for Structural Design
• Graz University of Technology - AG Sustainable Construction
• University of Natural Resources and Applied Life Sciences Vienna BOKU - Department of Spatial, Landscape and Infrastructure - Institute for Spatial Planning, Environmental Planning and Land Use Management
• WMV Immobilien AG

DI Maike Gold
Lessingstraße 25/IV
A-8010 Graz
Tel.: +43 (316) 873 6291
E-mail: maike.gold@tugraz.at
Web: www.counterintuitivetypologies.com