In recent years, the construction industry has developed into one of the largest economic engines in Austria, partly because many other sectors are dependent on it. Although the current corona crisis has caused this engine to stutter, construction has nevertheless performed significantly better than other sectors of the economy due to the restrictions imposed by the pandemic. Residential construction in particular continues to run at a very high level and is currently attracting the attention of numerous international investment houses, which are buying one housing project after another in the federal capital. Properly implemented, the construction of buildings can not only set the course for a faster economic recovery of upstream and downstream sectors but can also continue to act as one of the biggest levers for achieving climate goals. Wolfgang Kradischnig and Rudolf Stürzlinger, CEOs of Delta Podsedensek Architects ZT GmbH, and Peter Podsedensek, co-founder and co-owner, see the key to sustainable construction and explain four essential pillars.
Vienna, November 24, 2020: Although residential construction in Austria is experiencing a slight decline due to the corona crisis, experts do not expect a long-term slump. According to the Austrian Federal Economic Chamber, a 20 percent decline in building permits is expected over the whole of 2020. The pre-crisis level was remarkable: in 2019, around 79.000 residential units were granted building permits throughout Austria. The construction industry has a key role to play in the climate debate: “Around 40 percent of energy consumption in the EU is accounted for by the construction industry. The same applies to around 50 percent of all transport, 35 percent of all waste, and 30 percent of CO2 emissions. The way we build today has a significant impact on our resource and ecological future,” says Wolfgang Kradischnig, CEO of Delta Podsedensek Architects. He sees the key in sustainable construction. For this reason, the DELTA Group co-founded the interest group Lebenszyklus Bau (Life Cycle Construction) in 2011 and has since then continuously expanded it together with many other industry partners. “We are setting a benchmark with various guidelines and have set ourselves the goal of creating more awareness of the life cycle in the real estate industry among public and private builders – away from the focused view of construction,” he continues. According to the expert, the following four pillars, among others, are crucial for smart, sustainable construction.
1. Think mobility holistically
“It is not too long ago that mobility in connection with building development was only taken into account by creating sufficient parking spaces. In the meantime, mobility behavior has changed – especially among the younger population. The availability of bicycle parking spaces and a mobility offer in the vicinity have moved into the focus of the residents,” says Rudolf Stürzlinger, CEO of Delta Podsedensek Architects ZT GmbH. Intelligent and affordable energy concepts are needed to meet the changing climate conditions in social housing as well. Summer overheating plays a very important role in the overall design of a building. The combination of different measures leads to a comfortable indoor climate in summer. “If you want to build climate-neutral, you build where residents can do without their cars. For example, building on a greenfield site is much less sustainable than a project in a city center, even if the new building is constructed in passive house quality,” the housing expert continues. After all, he says, urban sprawl is being pushed forward, along with the cost of providing infrastructure and a much higher level of mobility.
2. Planning energy efficiency in advance
Energy-efficient building with renewable primary energy supply means ecological and affordable living in the long run. Ambitious energy standards in new buildings are an investment and avoid costs in the future. Meanwhile, several studies refute the prejudice that energy-efficient building is expensive. The small additional costs during construction are more than compensated in the life cycle by the reduced energy costs. According to Kradischnig, what counts is where the energy comes from: “We need more and more cold, heat and electricity. We have to produce these from renewable sources and decouple the buildings from fossil energy and CO2 emissions. This means that renewable energies must not only be installed retrospectively at a great technical effort but must also be planned as part of the low or plus energy building”. This begins with the orientation of the building in order to be able to use as much solar energy as possible, both actively and passively. “Even in the subsidized housing sector, the topic of energy is becoming increasingly important. For large-volume residential buildings, panel heating and cooling via the ceiling are increasingly being used. This system will establish itself as a standard for some housing developers. Ventilation systems are viewed rather critically because of the hygiene criteria and the high maintenance requirements,” adds Stürzlinger.
A recent survey by the DELTA Group shows that customers generally attach importance to sustainable aspects on a scale of 1 to 10 (1= low, 10= high) – the average value is around 7.4. These include, for example, “cradle-to-cradle” (recycling management), life cycle costs, partnership-based cultural design, or ecological balance. Customers across all industries would even spend an average of about 10 percent more on sustainable projects. There are different views regarding the current situation due to coronavirus. Some test persons were of the opinion that there will be a change towards more climate-conscious building. Others, however, did not see the corona crisis as a reinforcement of this trend.
3. Reorientation in building materials
When using the raw materials for construction, the awareness should be increased to avoid composite materials and to pay attention to the later separability of the building materials. Preference should also be given to recyclable materials. One possible approach to increase the use of recycled materials is urban mining. Here, the resources of modern cities are used to ensure the efficient recovery of materials. In this concept, cities thus function as raw material deposits whose existing resources of buildings and infrastructure are reused. “Urban Mining has arisen primarily because the EU has realized that primary resources will become increasingly scarce and thus more expensive in the future,” Kradischnig says. “Building ecology is currently still being neglected due to the price pressure in subsidized housing construction. However, the advantages of ecological building materials such as wood result not only in short construction times and a high degree of prefabrication but also in a healthier and improved indoor climate,” emphasizes Stürzlinger.
4. Consider different life situations
Residential construction means flexible adaptation to technological developments and changed the living conditions of the residents or the addition of completely new use. Above all, expertise is required for subsequent densification: the requirement is to create valuable conversions and to be able to create housing and living space from commercial areas or other types of buildings. “Mixed uses with apartments on the upper floor and with services such as kindergartens or stores on the first floor are becoming increasingly important,” says Stürzlinger. With the right planning, flexibility and quality of life can be achieved through barrier-free access, generational and gender justice, and equal opportunities. Suitability for everyday use is essential for a residential building. It should address different user groups and at the same time take social aspects into account. This is achieved through different forms of living and multi-purpose floor plans, but also through outdoor areas such as green spaces or playgrounds. Bicycle and stroller storage rooms make everyday life easier, as does a possible combination of working and living, for example by renting workspaces close to the apartment.
In order to promote sustainable projects in the construction industry, the DELTA Group has created a so-called “DELTA green line” within the company in 2012. This has created an overall concept for the life cycle-optimized planning of the real estate. A number of projects in which Delta Podsedensek Architects ZT GmbH is also involved have already been implemented and even awarded prizes – for example, the IFA Tulln (Interuniversity Department of Agricultural Biotechnology) and the office building Ekom in Piešťany (Slovakia). Only recently, a current project, the Buwog project “Kennedy Garden” in Vienna, was awarded the “Green pass” certificate about one month after construction began. Green pass recognizes climate-friendly urban planning and analyzes six thematic areas (climate, water, air, biodiversity, energy, costs). “In doing so, we show that sustainable living in urban areas can be implemented in an attractive way and set a strong signal for future projects,” Peter Podsedensek is convinced.