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The city of Tartu installed automated systems in old housing blocks. Using nudges, sensors, and automated decision-making, it hopes to reduce energy consumption by two-thirds.

SmartEnCity is a Europe-wide project that aims to transform cities to become carbon neutral. Tartu, a small campus town in Estonia and home to around 100,000 people, is one of the “demonstrator cities” for this project, which it called Tark Tartu (Smart Tartu). As part of this project, the city introduced a public bike-sharing system, bought gas-powered buses, and installed automated LED streetlights that take into account local weather and traffic conditions and adjust lighting levels accordingly. The city authorities are also retrofitting Soviet-era “khrushchyovkas” into “smartovkas”. This means turning old concrete-panel apartment blocks into modernized, “smart” living spaces.

Khrushchyovkas dot the cityscape of most former Soviet countries. In Estonia, they are an integral part of many neighborhoods. They have housed several generations, although they were originally built to last 50 years – an estimate that was revised upwards by successive governments. The buildings are now thought to be fit for another half-century if properly renovated.

These concrete-panel apartment buildings were built between the 1950s and the early 1970s, when Nikita Khrushchev was the first secretary of the Communist Party of the Soviet Union, hence their nickname of ‘khrushchyovkas’. They were easy and cheap to build, and millions of people still call them home.

In 1991, Estonia became independent from the Soviet Union, society moved on, the economy grew, and cities developed, but the khrushchyovkas remained. They are not without problems: heating is expensive because of subpar insulation, poor ventilation, and deteriorating plumbing. Also, many of these buildings have not been fully-renovated since they were originally built.

Apartment block renovation, to bring it up to current standards, is expensive, requires much work, and the responsibility usually falls on the inhabitants. Khrushchyovkas residents come from all walks of life and ages. Some people have lived in these buildings since the beginning. However, due to a lack of funds, leadership, or, perhaps, opportunity, many khrushchyovkas are in a less-than-prime condition, even though they sit in desirable locations in Tartu.

Taking the opportunity of European funding, some of these buildings were incorporated into a pilot program that promised to make them energy-efficient, high-quality living environments with embedded, automated systems.

Upon closer inspection, the reality is far from a futuristic, ultra-modern, automated smart home, but the project is a work in progress, and the real results will only become clear in the years to come. The goal is to renovate and “smarten up” 17 apartment buildings located in the center of Tartu. The systems are still under development, however, there are already tangible results. “Of course, I’m happy. The heating bills are lower, and I do not have to report my warm water and gas usage manually anymore,” said Anatoli, whose house was renovated, as part of the project, in the summer of last year. “My home is finished, and everything works. But in some apartments, gas and electricity consumption indicators are still not showing,” he added.

“The goal is to get the building’s energy rating as good as possible, and, for that, the inhabitants have to contribute with their behavior,” said Tõnis Eelma, who is one of the project’s leads and the chairman of the apartment association of his building, which was the second bloc to be renovated as a part of the project.

“Every apartment has a tablet attached to the wall where residents can monitor their consumption and, we hope that, based on that information, people adjust their habits,” said Mr. Eelma. The ultimate goal is to lower the building’s yearly energy usage from the current 270 kWh/m2 to 90 kWh/m2.

“One of the most revolutionary things is our demand-driven central ventilation system. This means that the carbon dioxide levels are measured, and the influx of fresh air to your apartment is regulated automatically,” said Mr. Eelma. The solution is unique, as, usually, renovated apartment buildings get a certain amount of fresh air throughout the day regardless of whether you are home or not. The other option is that there are pre-set ventilation intervals, which only take into account people’s 9-to-5 schedule, but not the ones who are home all day, such as the elderly.

Raivo Raestik is the CEO of Enlife, the company that won the tender to develop the smart home systems for the “smart-ovkas”. He explained that the tablets enable two main things for the inhabitants: monitoring information about themselves and controlling their indoor climate. The system records electricity, water, and gas usage for each apartment, uploads the data to a cloud environment, and shares it with various stakeholders, such as the city of Tartu.

Users can view their usage statistics, the current and desired inside temperature for all rooms, CO2 levels (measured in parts per million), and the outside air temperature. They can also check the time and greet guests through an intercom system. And if they previously had to state their hot water and gas usage to the utility company, it is now automatically read remotely.

Ten out of the 17 buildings opted to have their building upgraded with radio connections as opposed to cable connections, meaning that their sensors are all wireless. Smart home systems also allow the user to check battery levels for those remote sensors, such as the smoke alarm or thermostat.

Users can control the temperature and ventilation and monitor their statistics, using the tablet installed in the apartments, through a computer web interface or a smartphone app. Control over ventilation was given to the inhabitants in case they are not happy with the level of fresh air input chosen by the system.

Seeing statistics is part of raising energy-consumption awareness. Tõnis Eelma said that in the future they would like to offer the option to compare an apartment’s energy usage to the rest of the building. The building would then get an average, which in turn could be compared to the other renovated apartments in the project, which could introduce an element of competition.

But it might not be so simple, due to different ways people think and live. “We are still discussing what to compare and with whom,” said Mr. Raestik. ”The first comparisons were made with the building’s average.” Those statistics were generated by calculating the usage of all apartments. “But the apartments are very different. You can have an elderly person living alone or big families – that’s apples and oranges. If you see that your usage is +156% of the average, then that does not motivate you to save energy.” EnLife is rather looking to develop a statistical comparison related to each resident’s past behavior. “But that also needs some thought because you cannot indefinitely lower your energy consumption – you still need some level for your basic activities. We do not want people to get discouraged when they cannot lower their energy usage levels anymore.”

However, the development is still in progress. Mr. Raestik said that one of the next things in the pipeline is to deliver automated scheduling for temperature levels so that people can have lower temperatures at night without having to manually change the temperature via the system’s interface.

In addition to the smart home system, the apartments were fitted with solar panels, insulation for the walls and roof, a new heating and plumbing system, new windows, and outside doors.

No solution like this existed in the market before. In Estonia, smart homes have a reputation for being expensive and complex. Few people have these solutions in their homes unless already provided by the developer. Retrofit- ting homes to become smart is uncommon. The Smart- EnCity project ordered a one-size-fits-all solution. EnLife started by developing it for about 600 apartments. They designed everything in a way that allows for retrofitting all the homes in case of future changes because the smart home system is evolving together with the SmartEnCity project.

Comparing this smart home system to Apple Home, Sam- sung SmartThings, and Google Nest, Mr. Eelma said that there were two main differences: those solutions would not have fit their budget, and they do not focus on energy consumption. The goal of the project is to raise awareness among people about their habits and inspire them to change their behavior to save energy.

Mr. Raestik added that when you create a smart home system at such a large scale, they must consider technical support and continuous updates for as long as the building stands. “In my experience with big players, as time goes by, tech-support for older versions gets discontinued,” he said.

The city’s total investment to retrofit 17 buildings is around nine million euros, plus 400,000 euros to develop the smart home solution. The exact cost of each building’s renovation depends on a tender. “Our building had 32 apartments, and the renovations cost over a million euros. We had to cover around half of that by taking out a loan,” said Mr. Eelma. Using Horizon 2020 funds, the city of Tartu helped cover 25% of the total cost, and the rest came from a national renovation grant.

The first results show that, on average, heating bills have been cut in half. “We were hoping that they come down to one-third of the original cost, but we must consider that, before, heat was only used to warm radiators in apartments. Now, in addition to that, it heats water and air in the central ventilation system,” said Mr. Eelma. “But the monetary win is small because while we can save from consuming less energy, the loan payments don’t get any lower.”

The renovations came with some conditions. For example, the installation of solar panels was mandatory for all buildings to provide additional energy to the buildings. Furthermore, while all the energy-consumption data belongs to the inhabitants, they are obliged to share it (in an aggregated format) with the city of Tartu until 2021 to measure the effectiveness of the renovation program.

“It is a great project; we are testing a lot of new things. But it is not ready yet – fine-tuning the houses’ systems to lower costs is still ongoing,” said Mr. Eelma. With four years and some results already under its belt, this ambitious project hopes to prove that when you give people the opportunity to monitor their energy-consumption behavior, they will change their habits to save energy in the long run. You can only improve what you can measure.