An office building in central Poznań is taking an unusual route towards energy independence. Skanska has completed 53 geothermal boreholes beneath Nowy Rynek C, creating the foundations for a heating and cooling system designed to operate without the city’s district heating network.
The boreholes, each approximately 250 metres deep, sit beneath the building’s foundation slab. Together, they will allow the development to draw on the relatively stable temperature of the ground throughout the year, reducing its reliance on conventional heating systems.
The project is part of the wider Nowy Rynek development near Poznań Główny railway station, where modern office buildings have transformed a former industrial area into a growing business district.
53 boreholes beneath the foundations
Installing dozens of deep boreholes beneath an office building requires careful planning. Before committing to the system, Skanska carried out geological investigations and thermal response testing to assess the ground’s suitability.
The results were used in computer modelling to determine the number, depth and spacing of the boreholes. This was intended to ensure the system could operate over the long term without excessively cooling or warming the surrounding ground.
Ground-source heat pumps use the relatively stable temperature below the surface to provide heating in winter and cooling in summer. At Nowy Rynek C, the geothermal installation will work alongside air-source heat pumps mounted on the roof.
A rooftop photovoltaic installation with a capacity exceeding 350 kWp will provide an additional source of electricity for the building’s energy systems.
The combination is designed to meet the building’s heating and cooling requirements without connecting to the municipal district heating network. It also gives the owner the option of sourcing all the electricity needed to operate the building from renewable sources, backed by guarantees of origin.
A different model for large office buildings
Ground-source heat pumps are not yet a common choice for office developments of this scale in Poland. The drilling work, upfront investment and technical complexity can make them difficult to incorporate, particularly when energy infrastructure has not been considered early in the design process.
Przemysław Kubaś, Project Manager at Skanska Central Europe, said the industry should be more willing to explore alternative approaches.
“In Poland, investors rarely opt for ground-source heat pumps in buildings on the scale of Nowy Rynek C. This is usually due to concerns about the complexity of the engineering process, the significant cost of drilling and a lack of early planning. We should be looking for new ways to design buildings and plan how they operate, including making bolder use of innovative technologies that enable low-emission heating and cooling.”
The decision also reflects the longer-term challenges facing commercial property owners. Energy efficiency, operating costs and the ability to adapt to changing environmental requirements are increasingly important considerations when developing and managing office space.
What the energy figures show
According to the building’s energy performance certificate, dated 22nd April 2026, Nowy Rynek C has a projected primary energy indicator (EP) of 44.32 kWh per square metre per year.
That is approximately 62% below the stated reference limit of 117 kWh/m² per year under Poland’s WT2021 building energy standards.
The figure indicates a strong projected energy performance, although it should not be confused with independently verified operating results from a completed and occupied building.
For the developer, reducing energy demand and moving towards an all-electric system are also intended to limit the building’s operational carbon footprint.
Konrad Ziejewski, Project Director at Skanska Commercial Development Europe, said the building had been designed with future energy and environmental requirements in mind.
“Commercial buildings being completed today must be prepared for the environmental and energy challenges of the coming decades. Replacing the municipal district heating network with an innovative combination of ground-source and air-source heat pumps and a photovoltaic installation makes it possible to eliminate the building’s dependence on external heat supplies, improve energy efficiency and reduce operating costs over the long term.”
Another step in Poznań’s changing business district
For Poznań, the project offers an example of how the city’s newer commercial buildings are approaching energy use differently. The results will be relevant not only to developers, but also to businesses choosing office space and property owners planning for future operating costs.
The system’s eventual performance will depend on how the building operates in practice, including its electricity consumption and the balance between heating and cooling demand across the seasons.
For now, the completed boreholes mark an important stage in the development. As work progresses at Nowy Rynek C, the geothermal installation, rooftop heat pumps and solar panels are set to form an integrated system intended to reduce the building’s dependence on conventional energy infrastructure.
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