5.4 Focal points for saving resources in the built environment

To achieve the objectives of the construction sector, the following focus areas, levers and associated activities are to be implemented in the coming years.

1. Structural foundations for resource-saving building construction and civil engineering
2. Saving resources in urban development
3. Resource-efficient infrastructure for services of general interest

Structural foundations for resource-saving building construction and civil engineering

The principles and methods of resource-conserving and circular construction must be developed in a practice-oriented manner and progressively embedded in planning and decision-making processes. Vienna has substantial scope for action in the areas of procurement, funding, quality assurance and the regulatory framework. This scope is to be utilised and consistently expanded in order to further sharpen established practice.

The DoTank Circular City Wien 2020–2030 programme of the City of Vienna is already making an extensive and valuable contribution in this regard.

BEST PRACTICE

Deconstruction of the Ferry-Dusika Stadium

Prior to the necessary replacement construction of the Ferry-Dusika indoor stadium, originally built in 1976, several tonnes of materials were carefully and professionally dismantled as part of a controlled deconstruction process and through social urban mining, and subsequently channelled into reuse. The project consistently applies circular-economy principles across the ZiFa categories: deconstruction and reuse, recycling, and disposal.

Digital twin of Wiener Netze

The digital twin of Wiener Netze (the City of Vienna’s energy and utilities grid operator) maps the City of Vienna’s supply networks for electricity, gas, district heating and fibre-optic cables, which together extend over a total length of 29,500 kilometres. This leads to increased resource efficiency in planning and construction measures.

Quotas for reclaimed asphalt

In the construction of roads, pavements and cycle paths, the City of Vienna uses reclaimed asphalt in new asphalt layers. This is regulated through quota requirements in the procurement of construction projects and thus contributes to saving resources in civil engineering.

Lever 22: Measurability of circular-ready planning and construction

To implement circular construction, clear definitions are required of what is meant by circularity. The development of circular materials, construction products and buildings requires standardised and reliable data as well as assessment methods which, despite the necessary technical depth, must remain easy to apply in practice. This in turn requires constructive cooperation among all stakeholders involved in construction activity.

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Lever 23: From theory to practice – circular piloting as a key driver of transformation

Pilot projects in the field of circular construction play a central role in shaping the transition from theoretical concepts to solutions that are viable in practice. Using concrete construction projects as illustrative examples, they show what is already possible today in circular new construction, the further development of the existing building stock, refurbishment and deconstruction, while at the same time making visible where existing framework conditions reach their limits.

These pilot initiatives are therefore far more than isolated cases. They function as strategic levers in the transformation process: they help to identify challenges, test scalable solutions and derive success factors with systemic impact. A key prerequisite is the systematic feedback and integration of insights with the relevant implementation programmes - such as the DoTank Circular City Vienna 2020–2030 programme -together with the evaluation and the targeted communication of these insights.

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Lever 24: Legal anchoring of circular-ready construction

The successful implementation of the circular economy requires clear legal framework conditions in order to deliberately drive the transition from a linear to a circular construction culture. This entails binding regulations and requirements governing the handling of existing buildings and further development, new construction, refurbishment and deconstruction, ensuring the sustainable use of resources and materials. At the same time, circularity must be integrated into existing requirements, structures and processes, for example in the field of quality assurance.

Initial legal steps have already been taken through the establishment of the circular economy as an objective of urban planning and enhanced protection of the existing building stock under the 2023 amendment to the Vienna Building Code, as well as through the promotion of circular construction methods and materials in the 2024 Refurbishment and Decarbonisation Regulation.

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Lever 25: Digitalisation and modern workflows for resource efficiency in construction

Digitalisation - in particular Building Information Modelling (BIM) - is a key tool for embedding the circular economy in the construction sector. BIM describes a working method for the networked planning, construction and operation of buildings, based on defined processes, roles and digital tools for project delivery and collaboration. This makes it possible to locate and anchor a wide range of material and product properties within specific building projects during the planning and development phase and to embed them within a life-cycle perspective. This ensures that resources are also used in a resource-efficient manner during the operational phase.

For the circular economy, it is essential that product and material properties are comprehensively documented and made readily accessible. Digitalisation does not solely mean increasing efficiency in work processes; it also enables the development of new, high-quality fields of activity that significantly improve decision-making and delivery competencies.

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Saving resources in urban development

Urbanity offers a wide range of solutions to climate and resource challenges. Decisive course-setting for the sustainable use of resources takes place at the level of urban development. Key contributing factors are urban density, mixed uses, long-term openness of use and the careful handling of the resource land. Soil protection, land take and resource efficiency are inextricably linked.

The Vienna Plan – Urban Development Plan 2035, adopted by the City Council in April 2025, places saving resources and the circular economy alongside climate mitigation and climate adaptation at the centre of urban development. From 2025 onwards, no additional urban development areas will be newly designated beyond those already identified. All urban development projects are required to comply with sustainable construction principles, durability in terms of adaptability and potential for change of use, and provisions for future deconstruction.

Areas of settlement development are connected to the high-capacity public transport network from the outset in order to enable resource-saving mobility for all. City-wide development therefore sets the framework for circular construction practices and makes a substantial contribution to achieving the City’s climate and resource objectives over the long term.

BEST PRACTICE

Circular-capable construction at Nordwestbahnhof

On the 44-hectare former Nordwestbahnhof railway site, Austrian Federal Railways (ÖBB), together with the City of Vienna, are developing a green, liveable urban quarter accommodating around 16,000 people and approximately 4,700 jobs. This large-scale project serves as a prototype for circular construction. Criteria from the Circularity Factor (Zirkularitätsfaktor, ZiFa) are incorporated into property developer competitions and architectural design competitions (for example in school construction), thereby ensuring the integration of circular-economy principles.

Circular Soil Wildgarten

In Vienna’s 12th district, a new residential area is being developed on the Rosenhügel that connects nature and the city. For local resource management, central areas are designated for construction-site facilities, including concrete production, as well as site-specific areas for the processing and temporary storage of materials. In addition, storage areas for the valuable topsoil have been leased in the immediate vicinity of the construction site.

Fritzi-Massary Park

The redesign of the former Offenbach Park in Vienna’s 2nd municipal district has developed into a flagship project for sustainable circular-economy approaches in public green spaces. Designers from the University of Applied Arts Vienna used materials from deconstruction projects and recombined them in creative new ways. This resource-saving approach not only led to savings in CO₂ emissions and costs, but also resulted in high-quality, durable features throughout the park.

Lever 26: Renewal of the existing urban fabric for maximum resource saving

Neighbourhood-based strategies, property-spanning concepts and inner-city new developments and further development, alongside high-quality refurbishment of individual buildings, form key foundations for implementing saving resources and the circular economy in the built environment. High-quality refurbishment of existing buildings reduces energy demand for heating and cooling and secures valuable building fabric over the long term.

The “Raus aus Gas” (“moving away from gas”) initiative must be viewed in conjunction with the circular city and circular-ready refurbishment. Structural and technical measures at building and neighbourhood level, as well as legal frameworks to reduce vacancy, are also crucial in this context. The careful use and further development of the existing city reduce the demand for resources required for new construction.

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“In all projects - whether within the existing urban area or as part of the necessary expansion of the city - climate and soil protection, as well as saving resources and the circular economy, come first. That is why conversion is prioritised over demolition, settlement development is land- and resource-saving, the land requirements of the energy transition and the circular economy are considered from the outset, and the transformation of the energy system is actively driven forward.”

Lever 27: Resource-saving urban expansion in urban development

Saving resources and the circular economy - alongside climate mitigation and climate adaptation - are to be embedded as central requirements in urban planning for new urban development areas such as Seestadt aspern or RothNEUsiedl. They are to be taken into account at both neighbourhood and building level. The land-saving and careful use of soil in urban development areas is a central objective of urban planning. This applies equally to the local reuse of excavated material and to soil-protection measures aimed at preserving soil functions.

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Lever 28: Circular design of urban open spaces

The planning and redesign of urban public space offer significant potential for implementing the 10-R principles (see also Chapter 3), for example through de-sealing and greening, as well as through the use of reused and/or reusable construction products and recycled materials. Climate-resilient, attractive and multifunctional planning and design of public spaces play a key role in enabling everyday, resource-saving mobility in a “city of short distances”. They accommodate a wide range of different uses, made possible by high-quality spaces without pressure to consume.

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Lever 29: Logistics and spaces for circularity in the construction sector

Circular logistics brings together the need for land, mobility solutions, technical equipment and systemic, market-related structures required to establish a (digital and physical) marketplace for circular-ready construction, production and use (see also Chapter 3). Owing to their particular importance for the construction sector, the topics of land and logistics are explored in greater depth here, complementing Lever 3.

In future, a supra-regional exchange of resources for the Vienna metropolitan area is intended to harness the potential of circular material loops. This requires suitable land and high-performance logistics structures capable of managing the resource flows that are expected to increase as a result of regional circular practices. To this end, both larger regional industrial companies and large-scale logistics sites (for example the Port of Vienna), as well as local, decentralised units (for example craft enterprises and small and medium-sized enterprises), need to be involved. Wherever possible, existing structures (for example available land for interim storage) are to be used.

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Lever 30: Circular management of excavated soil

Excavated soil plays a special role in the circular economy. On the one hand, it represents a particularly significant volume: more than half of all waste quantities recorded annually in Austria originate from excavated soil. On the other hand, depending on their quality and compaction characteristics, excavated materials can be used directly for backfilling, greening measures or land recultivation. The biological and chemical transformation processes affecting humus-rich topsoil, as well as the differing qualities of the individual soil layers, result in the need for re-layering intervals. Challenges relating to interim storage, logistics processes and, not least, demand steering currently hinder rapid, straightforward reuse.

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Resource-efficient infrastructure for services of general interest

Vienna differs from many other major European cities in one key respect: a large proportion of essential urban infrastructure is owned by the City. Under the umbrella of the Wiener Stadtwerke Group, key infrastructures are operated in the fields of public transport (Wiener Linien, Wiener Lokalbahnen), parking management (WIPARK), energy supply (Wien Energie, Wiener Netze) and funeral services (Bestattung und Friedhöfe Wien). Wien Holding, with its logistics companies (Port of Vienna and the Vienna Wholesale Market), ensures the supply of goods for everyday needs in Vienna. Vienna Water supplies the City with drinking water. Wien Kanal is Austria’s largest sewer network operator. The main wastewater treatment plant treats around 680 million litres of water every day to a very high standard.

This overview makes one point clear: together with its municipally owned companies, the City of Vienna holds key levers for saving resources and for the circular economy.

BEST PRACTICE

Waste2Value – fuel from residual materials

Under the Waste2Value project, residual materials are converted into environmentally friendly, CO₂-neutral fuels. At a pilot plant in Vienna-Simmering, a so-called synthesis gas is produced through thermochemical conversion, serving as the basis for the production of green hydrogen, biogas and renewable fuels. During the test phase, materials processed include sewage sludge, residues from the paper industry and contaminated waste wood.

Recycled concrete at the U2 emergency exit Quellenstraße – Green Infrastructures

Concrete inevitably plays a central role in the expansion of Vienna’s underground lines U2 and U5 - one of the City’s largest climate protection projects. Recycled concrete is also being used in this context, alongside alternative reinforcement solutions. The practical application can be seen in a tunnel wall at the U2 emergency exit at Quellenstraße, where recycled concrete was used in the construction of the tunnel wall.

1,600 public drinking fountains to avoid plastic bottles

The City of Vienna maintains around 1,600 drinking fountains as well as 55 monumental and memorial fountains across the entire city area. Drinking fountains can be found, among other places, in parks, on playgrounds and near markets - where they provide free, readily available refreshment and thus help to avoid large quantities of plastic waste generated by the purchase of bottled drinks.

Lever 31: Resource-efficient mobility

The use of public transport is a central lever for linking climate mitigation and the circular economy. Public transport and active mobility (such as cycling and walking) conserve our space and material resources. They use space and materials far more efficiently than private car traffic, both in motion and at rest. They create space for urgently needed climate-adaptation measures in public spaces (such as de-sealing and greening) and, unlike motorised transport, do not introduce additional heat into the city. Public transport and active mobility therefore form the foundation for a resource-saving and healthy way of life.

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Lever 32: Resource-efficient water and wastewater systems

Thanks to the Alpine spring water pipelines (Hochquellleitungen), Vienna has historically enjoyed very favourable conditions in the field of drinking water supply. In the context of the climate crisis, the high-quality preservation, maintenance and expansion of Vienna Water’s drinking water supply system and the sewer network as central infrastructures have become increasingly important. The expansion and upgrading of green spaces required for climate adaptation lead to higher water demand during the summer months. Heavy rainfall events result in locally very high loads on stormwater management systems. The continuation of Wien Kanal’s innovation strategy, together with Wien Energie and other business partners, represents an opportunity to further strengthen environmental protection and circular-economy efforts.

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Lever 33: Circular economy in climate-neutral energy systems

Strategic directions for the decarbonisation of Vienna’s energy supply reduce the consumption of fossil resources. Refurbishment of existing buildings increases energy efficiency and extends their service life - a flagship example of the close linkage between climate mitigation and saving resources.

There is considerable potential for resource efficiency, including in the use of materials in the thermal retrofitting of buildings, in the construction and maintenance of energy supply infrastructure, and in the maintenance and replacement of technical building services and systems (such as fossil-fuel heating systems). This will in future give rise to numerous opportunities for cooperation in the recycling and reuse of technical systems and equipment that are no longer required.

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