Vienna is active on passive public housing

Eco-friendly, low-energy building – including social housing – is fast becoming the norm in Austria’s historic capital


Eco-friendly, low-energy building – including social housing – is fast becoming the norm in Austria’s historic capital

VIENNA HAS always been a city of progress, a place where thinkers and artists have broken new ground in disciplines as varied as psychoanalysis, music, philosophy, and literature.

The modern city is at its most innovative in its architecture, and particularly its public housing. Vienna is a world leader in the construction of “passive” buildings. These have a minimal impact on the environment, and draw most of the energy they require from “passive” or renewable sources.

Passive buildings are designed and constructed to exacting standards, employ safe and sustainable materials, and are cleaner and cheaper to heat or cool than traditional buildings. Thousands of Viennese already live in them; tens of thousands more will in decades to come.

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The city’s housing policy originated in the late-Hapsburg period. Imperial Vienna was a fetid, overcrowded place. Over the last five decades of the 19th century its population quintupled to two million.

As the municipal authorities had made no provision for such rapid growth, a severe housing shortage developed. Thousands had no choice but to sleep on the freezing streets; those who could afford to, rented a bed for a few hours.

In this age of political and cultural ferment, the homeless and destitute mobilised. Eventually, facing continual demonstrations, some of up to 100,000 people, the authorities accepted the need to act on homelessness. They agreed to provide sites, building materials and professional advice to people willing to invest thousands of man-hours in the building of their own homes.

Today, as the largest homeowner in Austria, the City of Vienna co-finances not-for-profit housing associations to provide the majority of social housing developments. These associations are given tax advantages and are obliged to reinvest most of the profits in building new homes. Only projects which meet high architectural, and ecological and environmentally friendly standards are eligible for public grants; the lower the energy demand of the building, the higher the grant.

All new housing projects receiving grants are submitted to a special committee or a competitive process.

Sixty per cent of all Viennese households live in subsidised dwellings, and the City of Vienna invests in the completion of between 5,000 and 7,000 subsidized apartments per annum – about 80 to 90 per cent of the volume of new homes.

The municipal housing sector has had for a number of years now a strong green focus for both new- build residential units and the housing rehabilitation energy programme of post-war Vienna buildings. Passive building is fast becoming the norm in the city.

Since 1998, all publicly-subsidized new housing developments have had to meet exacting new low-energy standards. Passive buildings are roughly ten per cent more expensive to construct than traditional buildings. The environment benefits from the passive buildings due to reduced greenhouse gas emissions, reduced heating costs and speed of construction. One 18-unit residential apartment block built to passive standards was completed in Vienna in one week.

Vienna already has completed 12 passive developments, and work is well underway on Euro Gate, a 2,000-unit residential project which will be the largest passive development in Europe.

All apartments in the project will meet the criteria for passive buildings developed under the Austrian climate protection initiative.

The apartments are co-financed by the City of Vienna, on a 22-acre site of the former Asprang station in the 3rd district, a central location in the City.

Euro Gate originated in a Norman Foster master plan, with a resultant architectural design competition. Five different property developers were awarded contracts for seven different building sites.

Its central location in Vienna, within easy reach of the city centre by public transport, helps explain the high level of interest in the project. As of late September 2010, 2,000 people had applied to rent one of the first 71 apartments, which will become available in December under phase one of the scheme. Over the next few years almost 2,000 more apartments will become available. The tenants will have the option to purchase their homes at market value after renting and residing in them for 10 years.

The residents of Eurogate will save around €230 a year on their heating bills, and greenhouse gases are about 500kg below the emissions of low-energy buildings. The complex will draw energy from passive sources and the residual heat energy demand will be filled by a district heating system which in part uses decomposing garbage. Prospective developers submitted the energy demand of the units at tender stage.

Five different property developers were awarded seven building projects.

Euro gate is built with people in mind. The innovative and ecologically sensitive buildings are cited around a green area and an artificial lake.

The designers make great use of climbing-plants, fruit-trees and roof gardens. Seats, benches and a playground encourage adults and children to dally in, rather than hurry through, the courtyards.

All apartments are south or west orientated so as to receive maximum sunlight. The building envelope is well insulated, and windows are triple-glazed to ensure quiet within and reduce energy loss.

In summer, heat is dissipated through the ventilation system while building elements such as screening, loggias and arboretums, together with tree-lined paths offer shade. In winter, warm filtered air circulates in the apartments.

Eurogate is small-scale in comparison with Seestadt Aspern, the passive suburb scheduled for completion in 2028.

Aspern will be the largest urban development in Europe, housing 20,000 people and creating employment for 20,000 more in its offices and workshops. Even before the building work gets underway Aspern’s transport infrastructure will be in place.

The new suburb will be less than half an hour from the centre of both Vienna and the Slovak capital, Bratislava.

Austrians are now working on a new generation of passive buildings. These are known as “zero energy” and “energy plus” buildings.

The first is a building that requires little or no energy to heat its interior to the comfort level of 21 to 23 degrees. The second generates enough passive energy to satisfy its own needs and sells the surplus to the electricity grid.

A visit to Austria is a humbling but instructive experience for an architect from Ireland. Austrians emphasise the planning and design we neglected during the boom. Most Viennese housing complexes are not built for profit. And above all Vienna is proof of the link between public control of housing provision and building quality.

Would Ireland gain from adopting passive construction? A government-lead programme of retrofitting our buildings to passive standards could create work for our construction industry, make our buildings “cleaner” and more comfortable, and reduce our heating bills.

And there are other good reasons for embracing sustainable construction. For one thing we dont have any choice. The EU requires us to reduce our carbon emissions: a resolution of the European Parliament stipulates that from 2020 only “nearly zero energy buildings” will be built in the EU.

Then there is self-interest: we will naturally wish to avoid paying carbon taxes.

Retrofitting social housing, hospitals, schools and civic buildings would require state planning, incentives, and, yes, investment. But in return we would enjoy reduced heating bills and more comfortable buildings in which to live, work, learn and play.

  • Supported by the Comhar Sustainable Development Media Fund comharsdc.ie.
  • Frances Power is MD of FPA Architects fpa.ie