The legacy of Tartu's communist past can be found in the 100 'khrushchyovka' apartment blocks across the Estonian city. Nicknamed after Soviet Premier Nikita Khrushchev they were created from the 1950s onwards as temporary accommodation to deal with a chronic post-war housing shortage.

Nineteen khrushchyovkas built in the 1960s are now the focus of SmartEnCity, a new EU funded project attempting to design sustainable and resource-efficient cities in Europe. In Tartu it is working to rescue the buildings from an uncertain future by turning them into energy efficient 'smart homes' - a move that has earned them the new nickname "smartovkas".

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The project aims to create high-quality living environments that will encourage residents to move towards a more eco-friendly style of living. The apartments in Tartu will receive new insulation, windows and ventilation systems, as well as new central heating systems and solar panels. Each apartment will also get a smart home system which will enable residents for the first time to monitor and control their own energy consumption.

Before the renovation the housing blocks were nearing the end of their intended life-span

"The khrushchyovkas were not built with energy efficiency in mind," said Veronika Mooses, junior researcher at the University of Tartu, which is monitoring the SmartEnCity project. "The people living in the center can feel really hot during the winter, and the people living at the edges of the buildings can feel really cold." Built at speed and all to the same design, they were only expected to last between 30 and 40 years.

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Typically painted yellow or white, the soviet-era housing blocks are between three and five floors high. In Moscow thousands of these types of apartments are being demolished as they near the end of their life span. However, in Tartu the aim is to transform these buildings so they fit into the class-A category of energy efficiency — the highest category. Currently most are in class-F and the lowest class-H. According to Raimond Tamm, Deputy Mayor of Tartu and the city's SmartEnCity project leader, the ambitious project goes beyond the usual retrofitting activities the city has seen.

"It's a real challenge. And something I heard a lot at the beginning of the project is that it's not possible," said Tamm. However, he sees the potential impacts of the project as outweighing any challenges. He estimates if it is successful each apartment block will save two thirds of the energy they currently use. This means shifting from 270 kilowatt-hours per square meter per year (kWh/m2y) for each building to 90 kWh/m2y.

The project aims to reduce the energy consumption of each block by two thirds

Tonis Eelma, resident in one of the three khrushchyovkas already finished, said so far energy and gas consumption has decreased significantly. "This winter will be the moment of truth, but everything is much better already," he said.

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All the flats in his block are privately owned and the residents are a diverse group including both young families and those who moved in when the building was built in 1964. Initially it was hard to get the older people to agree to the project, he said, but at a mandatory vote to participate in the project only one person voted against joining.

Deputy mayor Tamm said the project has been criticized for its high costs. Each apartment building has cost around one million euros to renovate. Almost half the funding comes from the European Union, approximately 4 million euros, with additional contributions from a national support scheme. The rest of the money, around 50 percent, was taken out in loans by the housing associations. Some critics do not believe the apartments are worth saving and should be demolished, but Tamm argues this would not be a cheaper or easier solution.

Resident Tonis Eelma sitting on the roof of his renovated apartment block

Mooses said that for many residents the main incentive to take part has been to reduce their energy bills. Residents have had to take out a loan to part-fund the project which will be paid back over 20 years. In Eelma's building, which has 32 privately owned apartments, loan repayments will be around 100 euros a month per apartment. However these repayments are estimated to be balanced out by reductions in energy costs, said Eelma. Most other blocks have a lower repayment amount, as Eelma's housing association decided to also add balconies and other features at the same time.

"In 2019 the heat consumption has decreased more than 50 percent," said Eelma, adding that this heating is also now also used to heat tap water and ventilation air. "The gas consumption has decreased more than 80 percent and we have produced more than three times more electricity [from solar panels] than we consume for general electricity."

Megacities: Shades of green More parks wanted More than two-thirds of people will live in urban areas by 2050, according to the United Nations — but only some will live in cities where they can also enjoy nature. With just 2.2% of its land dedicated to public parks and gardens as of 2015, the Turkish city of Istanbul is one of the least green cities in the world. The government has proposed turning old public spaces into parks.

Megacities: Shades of green China's cities go green Figures collated by the World Cities Culture Forum show stark differences in urban planning in cities around the world. In Shenzhen, China, green space accounts for 40% of the cityscape, despite a booming construction sector that has dotted the city with skyscrapers. The crowded capital, Beijing, also says it's working to increase its urban green space, which is currently at more than 45%.

Megacities: Shades of green Benefits of green living Parks encourage people to exercise. Spending time among the sights and sounds of nature is also linked to better overall mental health. It relieves stress and improves well-being, as well as promoting social interaction. Despite its reputation as a concrete metropolis, about a quarter of New York City is green, with more urban gardens popping up on former industrial sites for residents to enjoy.

Megacities: Shades of green In the air we breathe Trees and plants also clean the air, so green spaces effectively make it safer to breathe. This is especially important in crowded cities like Tokyo, which according to a 2015 Bureau of Urban Development survey has just 7.5% green space. With a population of 9.2 million, many of whom are elderly, Tokyo's citizens are vulnerable to air pollution.

Megacities: Shades of green Keeping cool Concrete heats up cities and makes citizens more vulnerable to heat waves. This is called the urban heat island effect, meaning cities are typically much warmer than the surrounding land. But green spaces are a solution to this problem, as they help cool urban areas. Although public parks account for 35% of space in Los Angeles, the dense city is very familiar with the urban heat phenomenon.

Megacities: Shades of green Head above water Green spaces also absorb water to help prevent the kind of flooding seen in 2018 in Paris, some 9.5% of which is made up of green space. Engineered green spaces can even capture and purify stormwater runoff while protecting residential areas, making them a critical part of a city's flood management system. Paris is working toward planting 20,000 new trees by 2020.

Megacities: Shades of green Planning for the future Most emerging megacities, defined as having a population of more than 10 million, are in the global south. Bogota, Colombia, is a booming metropolis that dedicates 4.9% of its land to green spaces. As cities grow bigger and richer, they need to balance short-term economic development with the long-term health of citizens and the impacts of climate change. Author: Louise Osborne



One of the rules of the SmartEnCity project is that the results must be replicated, which is the reason the uniformly designed khrushchyovkas were chosen in Tartu. Estonia has an estimated 6,000 apartment blocks in total. The SmartEnCity team, which includes partners from the public and private sector, has already seen interest from other Estonian cities as well as places in Latvia, Poland and Bulgaria, countries which also have large stocks of Soviet-era housing. The project has partner cities in Denmark and Spain, where housing is also being redesigned to bring down energy consumption. Currently three smartovkas in Tartu are finished with the rest in the renovation phase.

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In Tartu initial reactions have proved surprising, said Mooses, who interviewed residents as part of her research. While there will also be new cycle lanes and bike sharing stations, buses running on biogas, and LED motion sensor street lighting which will also monitor air pollution, the part of the project that has really grabbed people's attention is the use of smart technology at home. Being able to monitor their own energy consumption and rethink their personal patterns of behavior through smart home systems, has made being more eco-friendly tangible in everyday life.

"People can really relate to this project," she said. "It's not like some data is recorded somewhere and people don't understand what it is. This [project] is directed towards spaces that are of the utmost importance to people: their homes."