Sustainability Report
Custom Certificates
Embodied carbon
Preservation of the existing reinforced-concrete structure
The most significant strategy is the retention and reuse of the wide-span reinforced-concrete skeleton of the 1972 bank building. Rather than demolishing the entire structure and replacing it with new construction, the project preserves the structural core and transforms it into the atrium and central hall of the hybrid complex. The former load-bearing structure becomes the defining architectural and spatial element of the new quarter. This is particularly important from an embodied-carbon perspective because reinforced concrete is carbon-intensive to produce. Retaining the existing structure avoids at least part of the emissions associated with constructing a completely new structural frame.
Social urban mining
The demolition strategy follows a hierarchy of:
- Reuse
- Recycling
- Disposal
Materials and components that can be reused are directed toward replacement neighbourhoods; materials that cannot be reused are recycled as raw materials; only materials that can neither be reused nor recycled are disposed of. The preservation of the reinforced-concrete frame is identified as the project's most significant reuse strategy.
Timber construction
The project uses wood extensively for:
- superstructures,
- trusses,
- prefabricated hotel-room modules,
- ceiling elements.
The hotel rooms are designed as prefabricated modular wood boxes, while glued-laminated timber is used for structural and ceiling elements. The architectural strategy is especially relevant because the existing concrete frame has limited remaining load capacity. The lighter timber construction reduces the need for major structural strengthening.
Reported carbon saving
The final report from the University of Innsbruck found that the project saved 1 ,500 metric tonnes of CO₂ equivalent.
Operational Emissions / Energy
Fossil-free heating and cooling
The project information states that the building has a 100% self-sufficient energy supply for heating and cooling and uses no fossil fuels for these systems. Heating and cooling are provided exclusively through geothermal groundwater and heat-pump technology. This is the project's strongest operational-carbon strategy.
Heat pumps
The klimaaktiv database identifies the building's space-heating system as a heat pump system.
Ventilation with heat recovery
The RLB office building includes a ventilation system with heat recovery, reducing heating losses associated with supplying fresh air.
Photovoltaics
The project also incorporates photovoltaic electricity generation. The planning-stage klimaaktiv information reported an annual PV yield of 88,740 kWh/year.
Energy-efficient building performance
For the office section, the klimaaktiv database reports:
- Heating demand: 26.0 kWh/m²/year
- Primary energy demand: 92.9 kWh/m²/year
- Operational CO₂ emissions: 12.8 kg CO₂e/m²/year
- PV annual yield: 88,740 kWh/year in the planning declaration
NB: The reported 12.8 kg CO₂/m²a applies to the RLB office building section assessed by klimaaktiv, not necessarily the entire hybrid RAIQA complex.
Service and maintenance emissions
Durable Facade Materials
The architectural design emphasizes the use of durable materials for the façade, which include glazing, metal mesh, aluminum, and exposed concrete. These choices are aimed at enhancing longevity and are likely to decrease the frequency of replacements throughout the building's lifespan.
Reuse of the Existing Structural Frame
By retaining the reinforced-concrete frame, the project can minimize life-cycle impacts. This approach extends the useful life of an existing structural asset instead of opting for an early replacement.
Prefabricated Timber Modules
The integration of modular and prefabricated timber elements can lead to more controlled manufacturing processes and may facilitate easier replacement or repair of components. However, the project documentation does not clarify if these modules are specifically designed for future disassembly.
Quality Assurance and Monitoring
The finalized klimaaktiv declaration includes energy monitoring, airtightness testing, and very low indoor pollutant values. These initiatives are crucial for ensuring operational performance and can aid in detecting any performance issues throughout the building's service life.
Afterlife
Adaptive reuse is one of the project's clearest and most significant sustainability strategies.
The project retains the core reinforced-concrete structure of the 1972 building and gives it an entirely different role. A previously densely occupied office structure is transformed into a large atrium and hall serving a hybrid programme that includes banking, hotel, events, art and shared public spaces. The retained structure is particularly adaptable because it becomes a large, open spatial framework, rather than being tied exclusively to its original office programme.
The wider building also incorporates several potentially flexible characteristics:
- a large central atrium and hall;
- hybrid bank, hotel, cultural and event functions;
- office areas organized as clusters;
- gallery-like consultation and meeting spaces;
- modular hotel-room construction based on the structural grid;
- large shared spaces capable of accommodating different forms of occupation.
The project demonstrates circular principles primarily through the retention of the existing concrete structure and social urban mining during demolition.
Key products in low carbon design
