Post City Linz - Biodiversity in the CO2-neutral urban quarter

Initial situation and motivation for the implementation of the R&D project

The former postal distribution center next to the Linz train station is currently undergoing a fundamental transformation from a virtually completely sealed infrastructural wasteland to a mixed-use quarter with approximately 150,000m² of gross floor area. An innovative mix of office, commercial, hotel, infrastructure and residential uses in 11 large-volume buildings and open and green spaces on several levels, which will be built in several phases over the next few years, will transform the formerly closed area into an open, connecting building block in the urban fabric in the future. Thanks to their central location, these "Post City Gardens" offer excellent conditions for the development of a neighborhood that is innovative from the ground up and conserves energy and resources. In order to seize this opportunity beyond what is usual in regular planning, the present exploratory project was initiated by Post AG together with the planning team and specialists in greening, biodiversity and energy.

Project content and objectives

The project focused on developing a bundle of measures as part of a systematic and coordinated approach. The main topics were biodiversity-promoting building envelopes and animal-friendly open spaces, a CO2-neutral energy supply and innovative energy management in the neighborhood, and rainwater management based on the principle of the "sponge city". In addition to examining the possible individual measures, the focus was particularly on the integrability of the topics of biodiversity, urban climate, rainwater management and CO2 neutral energy supply in the constructional realization and the ecological and economic effects of these measures.

Methodical approach

After a detailed analysis of the current state and the existing preliminary design plan, a variety of possible measures for the topics of biodiversity, building greening, renewable energy production, energy conservation and management, stormwater management and open space design were first examined and evaluated on a subject-specific basis and then cast into a coordinated implementation concept adapted to the specific architecture in interdisciplinary planning meetings. Inputs from subject matter experts, energy simulations, and the use of ecological assessment tools and life cycle cost analysis supported the decision-making processes.

Results and conclusions

The exploratory phase produced numerous results that, on the one hand, can be incorporated into the ongoing planning, and on the other hand, represent multipliable, generally applicable findings for the development of sustainable, resilient neighborhoods that conserve energy and resources. From the beneficial layering of greening, biodiversity measures and solar energy production on high-rise facades, to efficient urban greening technologies that optimize to the local microclimate, to detailed analyses of rainwater harvesting potential, numerous measures were investigated and incorporated into the implementation concept. With regard to energy management, the development of a cycle-oriented local energy concept using geothermal energy, photovoltaics and heat recovery from gray water reduced the annual CO2 emissions by almost 90% in comparison to a district heating and cooling concept. The present project also showed that the professional exchange between greening, biodiversity, rainwater and energy experts and architects at an early planning stage of such quarters is absolutely recommended and thus ecologically, economically and architecturally appealing overall solutions can be achieved without lengthy and costly re-planning due to non-coordinated individual measures. In the energy planning of such overall quarters, there is a great challenge in the conflict between the standard-compliant design of the heating and cooling systems and the actual demand in the utilization phase, which is not yet precisely known during the planning stage and tends to be overestimated in the case of standard-compliant calculation, which can lead to ecologically and economically disadvantageous solutions.

Outlook

The findings obtained in the exploratory study form the basis for ongoing planning and implementation and represent generally valid insights for the transformation of inner-city industrial and commercial sites toward resilient energy- and resource-efficient neighborhoods. The early consideration of local ecological conditions (microclimate, flora, fauna, water situation), analysis of local energy generation potentials and cycle-oriented energy planning must be an integral part of neighborhood planning processes in the future in order to meet current climate goals.

Project management

Österreichische Post AG

Project or cooperation partners

• AEE - Institut für Nachhaltige Technologien (AEE INTEC)
• Nussmüller Architekten ZT GmbH
• GrünStattGrau Forschungs- und Innovations-GmbH
• studio boden

Österreichische Post AG
Nachhaltigkeit & Gebäude-Compliance
DI(FH)Dkfm(FH) Andreas Frey
Rochusplatz 1
A-1030 Vienna
E-mail: andreas.frey@post.at