Positive-energy building in Kalasatama

Sweco is responsible for the integrated design of the upcoming positive-energy building in Kalasatama.

The pilot is a part of the EU’s EXCESS project. In the project, four pilot buildings will be constructed in different climate conditions around Europe. In addition to Finland, positive-energy buildings will be constructed in Belgium, Austria and Spain. The goal is to prove that we can move from low-energy buildings to zero-energy or even positive-energy buildings using existing technology. 

“This is a highly topical and essential project on our way towards carbon neutrality,” says Anne Lehtinen, Sweco’s architect and principal designer for the project. Lehtinen is in charge of the architectural design together with Sweco’s Responsible Construction Planner Simo Anttilainen. 

The EXCESS project is funded by the EU’s Horizon 2020 research and innovation programme. In Finland, the construction project is managed by Bassotalo. VTT is involved as a research partner. Corporate partners include Gebwell, Muovitech and Tom Allen Senera. The project is also a part of the City of Helsinki’s Re-thinking Urban Housing programme. 

Solar power and geothermal heating are critical  

In each country participating in EXCESS, the methods trialled for achieving positive-energy goals are slightly different. In Finland, energy efficiency is based on building service systems, says Jukka Lehtonen from Bassotalo. 

“We focus on a highly effective geothermal heating system, solar panels and smart control of the building services systems,” Lehtonen says. 

Sweco’s Specialist Responsible for Energy Design Joni Hilpinen says that Kalasatama is the most challenging one of the four pilot locations: energy is needed more during the dark and cold northern winters, but there is also less sunlight to produce the energy.  

Achieving the goal depends on how many solar panels can be fitted on the building’s facade. The solar panels will not be only on the building’s roof as usual, but also on its balcony railings, among other places, Anne Lehtinen adds. 

Rubik’s Cube can be solved through co-operation 

EXCESS involves over 21 operators from four countries. The team in Finland consists of many professionals. 

Sweco is responsible for the integrated design of the building in Kalasatama. Lehtonen states that having a single operator in charge of all planning areas is a definite advantage for a project.  

“It’s made things such as data transfers much easier. The planning is going full speed ahead,” Lehtonen says. 

Anne Lehtinen also considers it a benefit for the designers that all participants are from the same company.  

“Extensive urban projects are like Rubik’s Cubes. There are many parties and wishes to coordinate. It certainly makes our work easier that we’re all under the same roof.” 

Aiming at a reproducible concept 

EXCESS started in autumn 2019, and construction in Kalasatama will start in early 2021. VTT’s Energy Expert Ismo Heimonen says that VTT will collect data measured over a few years in the four locations in Europe and assess how energy efficiency is achieved. 

He points out that Kalasatama is a pilot location, and the goal of energy positivity may not be achieved, even though the team will do all they can. Even if this project does not achieve energy positivity, it may be possible to reach the goal on a smaller scale.  

The goals of EXCESS include not only proving that positive-energy buildings are possible, but also developing a reproducible concept through which the operating model of an positive-energy building can become a standard product in housing construction. 

Bassotalo’s Jukka Lehtonen agrees that, instead of simply achieving energy-positivity, the goal is to develop a concept with optimal energy efficiency to be used as a basis for future housing projects. 

“We’re not just working on this one project but a reproducible concept that can be developed further.” 

“Step by step towards zero and then towards positive values,” Heimonen summarises the idea.