Sustainable Buildings Retrofitting Notable City: Decarbonising Vienna

Notable City: Decarbonising Vienna

Karl Dickinson
Enthusiastic about real change that impacts real lives. Believer in the power of the individual; it can make all the difference. I enjoy connecting with people who have the wildest ideas and the enthusiasm to bring them to life.

Vienna is a pragmatic city, bursting with exuberance, diversity, and political action. In terms of decarbonising, it’s a place where people are making definite, positive urban change at the street and policy levels. We caught up with Peter Kraus, City Council Member for the Vienna Green Party (Die Grünen, Wien), to find out what other cities can learn from its approach.

Like any city, Vienna has its share of clogged roads, cough-inducing emissions, and energy-inefficient building stock. But with the Viennese and Austrian governments committing to being carbon neutral by 2040, change is in the (ever-less smoggy) air. Renewables and energy retrofitting play a major part in their plans.

Setting the Scene

The 2020 ‘Energy! ahead’ report from Stadt Wien (City of Vienna) confirms that “space heating and hot water account for approximately 40 percent of final energy consumption in Vienna”. “A lot of especially older flats are still heated with gas boilers”, Peter Kraus told us. And “it’s heavily based on fossil gas”.

This poses a problem: high levels of carbon emissions. “One of the biggest challenges,” Peter continues, is that “it takes a long time to change a heating infrastructure in an already-built city”.

Austria is a big fan of district heating, the warming of water and space using energy generated off-site and pumped into our homes and businesses. According to Euroheat & Power, it accounts for 14% of all the Republic’s residential heating needs. In the 1990s, half of the district heating (and cooling) came from fossil fuel sources, but now almost 50% derives from biofuels. Much of the rest from natural gas. Conversion from district heating to renewables isn’t mandatory, but this capital has committed to no longer using fossil fuels and is making inroads with phasing out the carbonising gas supply.

A concerted effort began in 2020. For a start, insulation is being put in place or renewed on a large scale in older commercial buildings and dwellings. Up-to-date buildings codes mandate fresh housing developments to come complete with PV panels, and “over 80 percent of new buildings will have climate-friendly HVAC systems” in place.

So, how did they get this off the ground? It starts with representation.

Power to the (Young) People

In Austria, the voting age is 16. But in addition to children – a climate-aware generation – there are “so many people living in Vienna, born in Vienna, who do not have citizenship and are not allowed to vote”. In some districts, Peter says, it’s as many as 50%.

Accurate representation, therefore, is a challenge. In Vienna, “there are different groups of people representing different groups in society”.

Peter himself “initiated something called Werkstadt Junges Wien” (Workshop Young Vienna) where 22,000 under-18s attended sessions to share thoughts about what they consider important about the future of their city. Even 4- and 5-year-olds “were just drawing how they think the city should look”. They formed an official youth-friendly city strategy, shaping environmental, social, even policing policy that was adopted by the local parliament. Outcomes are officially monitored and reported. And a youth parliament was set up with a €1 million children’s budget, which democratically chooses programmes to fund.

One project was made by 12- and 13-year-olds wearing a GoPro camera, filming young people’s experience of moving around the city through their own eyes. “This was sent to all the planners and to the traffic planners” who could suddenly visualise “that our city is not built for small people”. Now aware, they can make change happen. We know that traffic-calming benefits young people, so their input directly correlates to a cleaner city.

Cultural Decarbonisation – Embracing the Benefits

Despite ideologies skewing “opinions on different policy measures”, politicians were able to democratically agree on the goals for a carbon-neutral Vienna and “how we get there”. It’s a sign that the city’s leaders are taking “the challenge of energy efficiency seriously”.

“There’s no right or wrong in political opinions. There’s discourse, there’s discussion, and at the end of the day, there’s decision; and the decision can be good if it helps reaching goals.”

Spittelau power plant, Vienna
Image credit: Unsplash / Dmytro Shchetynin

The waste incineration plant in Spittelau powers Vienna’s district heating. As if to demonstrate the city’s relationship with decarbonisation, the facade was designed by internationally renowned artist Hundertwasser, making it an important cultural asset. Satisfyingly, this fulfills the most overlooked driver for retrofitting: aesthetics.

Another is occupant comfort. The City of Vienna’s ‘Smart City Wien Framework Strategy 2019-2050’ acknowledges that a “refurbishment drive has also drastically reduced energy consumption in the existing building stock”. It puts residents’ wellbeing at the heart of technological advancements and includes:

  • Generating much of the electricity on-site from renewable sources, including wall-mounted solar panels.
  • Greening facades – which double as vertical vegetable gardens, maintained by residents.
  • Cooling via evaporation from vegetation and water circulated around the building envelope.

Planning – and Acting – for the Future

“If you want to phase out gas, stop building your gas infrastructure.”

All the aforementioned actions point towards one objective: Vienna aims to be carbon neutral by 2040. “We voted on it, it is our goal”, Peter told us. This is where Vienna is exemplary – opposing parties are coming together to agree on climate goals.

He also spoke of how they plan to achieve it with a two-pronged attack written into city governance:

Rely on Renewables

The first is to completely power new constructions entirely with renewable sources. The transition is being phased in by administrative districts, what Peter calls “spatial planning”, where “it’s by law not allowed to build any new gas infrastructure or gas heating”.

Not an easy win when faced with the might of the wealthy fossil fuel lobbyists. It succeeded with the support of the people and politicians, “and we had a very good cooperation with a lot of building companies”. They know it’s better to build in a way that constructions are “still worth something in like 20 or 30 years”. In other words, they’re future-proofed.

So committed is the town to redefining its power supply, that the City of Vienna’s website provides interactive maps showing, among many options, the extent of waste heat, the potential for geothermal infrastructure, and the location of subsidised PV units. It’s a helpful resource for anyone looking for energy training providers, too – a clear sign the city is gearing up for an energy revolution.

But where do the thousands of historic properties fit in? Cue strategy 2.

Route of Least Resistance

Large buildings often have “a very complicated ownership structure”, with maybe up to 30 different arrangements, each unit with its own gas boiler. They can’t all be retrofitted-out in one swoop, and individual dwellings can’t choose to change how they are powered because alternative infrastructure isn’t yet in place.

Citing the experiences of a single technician, Peter explains how “on-the-ground knowledge” is the answer for “how to deal with complex situations” like retrofitting Vienna’s older homes, shops, and offices.

This proved a complex conundrum for working groups and combined financial and governmental groups for a long time. Years. Then along came one technician from Sozialbau, a Gemeinnützig (non-profit) building social flats in Vienna, who changed it all.

“He had a very simple solution: whenever there was a gas boiler that needed to be replaced, he didn’t replace it in the flat, he replaced it on the roof of the building.” Each flat gained space as their new boiler was relocated. Eventually, the whole system was centralised and could be changed altogether. Sometimes, the simplest solutions are the most effective.

Vienna “adopted the idea”. They had a solution they were proud of, one that can easily be replicated elsewhere, so “they showcased it everywhere”.

Community Engagement

Vienna has succeeded where so many cities struggle, because it involves stakeholders, Peter says.

As a politician, he understands the necessity of communicating with communities; as a CityChanger it’s important to “talk to everyone; to house owners, to developers, to people living there, to businesses, everyone who is part of the neighbourhood”. It’s not just about telling them what’s going on, or what you plan to do. You want them to get involved, to take responsibility.

“Make it their challenge to develop a plan together on how to phase out the fossils.”

Their Smarter Together programme trialled tenant participation (“wohnpartner” in German), which involved prescribing discussions relevant to tenants’ concerns, rather than top-down information dissemination. Such was its success, that the communication strategy will be rolled out to engage a quarter of Vienna’s 1.9 million residents.

Free Money is a Challenge

As with every success story, it’s not all a bed of roses. Money is a thorn in the side for Vienna’s strategic-led retrofitting programme.

The city administration offers subsidies for phasing-out gas. But in return for supporting individual households, they expect specified defined returns: “You need to achieve certain energy-relevant goals and one of them is to get rid of your fossils.”

“This worked perfectly fine until money was very cheap on the market, no interest rates, so it was quite easy to just take private money; if you wanted to retrofit your building you didn’t need the city anymore.” So, the city “can say we want more for” the money they offer, but its demands are proven to lead people to borrow from less concerned sources, making less impact.

What’s the solution? “I think that the most crucial part here is to stop funding the wrong things,” Peter says, “stop funding projects for climate policies, funding projects for mitigation measures.” And, of course, “stop funding motorways, stop funding gas infrastructure, stop funding fossil mobility”. Instead, make that money available for projects that genuinely put the future of the environment and society in the spotlight.

Carbon Budget

If you’ve heard Greta Thunberg speak of the urgency of climate action, you may be familiar with carbon budgets. This is the limit of CO2 we can release into the atmosphere without tipping global temperatures above 2°C compared to pre-industrial levels.

“CO2 does not know any city limits.”

Peter Kraus

Vienna challenged itself to align its €12 billion annual city budget with the carbon budget. “We are looking at every euro that is spent in Vienna – does it trigger CO2 emissions or maybe help reduce CO2 emissions?” Difficult, but bold steps are needed.

Vienna is no longer saying “new motorways are important and climate neutrality is important”, which is conflicting! Instead, the city is shifting away from car-centrism; it has already demonstrated this commitment with the pedestrianisation of the Mariahilfer Straße shopping district.

Conclusion – The Future for a Decarbonised City

The momentum has started. As a Viennese resident, Peter has grand visions for his CO2-free city: “You can go around the city by really good and cheap transportation. Public transport is 100% electrified and powered by clean energy, by renewable energy. Maybe sometimes you need a car, and you can easily access one of the car sharing companies that also runs on renewable energy. You have a lot of bike lanes and good areas to walk around the city because the city’s super walkable and accessible.”

So far so good. What about buildings?

In a time when climate change “is real and you feel it in everyday life” cooling will be a bigger issue. It’s all about being smarter. Thinking ahead. “The city was clever enough to also invest in retrofitting your buildings with sun protection outside of your windows, so you don’t need to install air condition that needs a lot of power”.

“So, you have a good life here, you have a very high quality of life. And you don’t need to burn any fossil fuel for it.”

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