‘Smartovkas’ are the most energy-efficient reconstructed apartment buildings in Estonia

25 Jun 2021

The old Khrushchev-era apartment buildings that were renovated in the SmartEnCity project in Tartu have become the most energy-efficient apartment buildings in Estonia – both according to thermal imaging and latest data.

Initial comparison data shows that the energy consumption in these buildings has dropped by 43% on average. “The 17 downtown apartment buildings that have been reconstructed with support from the SmartEnCity project have now become the most energy-efficient reconstructed apartment buildings in Estonia,” the Deputy Mayor and SmartEnCity project manager Mr. Raimond Tamm commented. “The apartments’ indoor climate has improved dramatically with the help of the novel CO2-based ventilation systems.”

In addition to a thick insulation layer, all buildings received a demand-based ventilation system with heat recovery and solar panels on roofs. During the renovation, all windows were replaced with triple-glazed windows and the cold bridges around the windows were reduced. In February this year, the project team commissioned new thermal images of the renovated buildings and compared them to the images taken of the same houses before the renovation: in the new buildings, the blue on the image that illustrates the cold spots with heat loss, has disappeared completely and the houses are a uniform color, showing very little heat loss.

The project team has data on more than half of the renovated buildings from 2020. Initial data shows that the energy need in the reconstructed buildings has been reduced on average by 43%. Grid electricity consumption has reduced by 27% and natural gas by 58%. The buildings also required 43% less district heating, although even less is spent directly on heating, as part of the district heating is now also used to heat domestic water, which was previously done with gas or electricity.

According to Mr. Kalle Virkus, engineer at Tartu Regional Energy Agency, these results are not final as several reconstructed buildings were completed only a year ago. The final energy savings is achieved a year or two after reconstruction once the technical systems have been optimized and residents have gotten used to the new technology.

All in all, 17 apartment buildings have been renovated in Tartu with the support of the SmartEnCity project, the 18th building will be reconstructed by summer 2021.