Caverion has secured a major contract with Nebius DC Oy to deliver comprehensive technical solutions for the expansion of Nebius’s data centre in Mäntsälä, Finland. The agreement, valued at approximately EUR 80 million (approx. USD 86 million), includes cooling, heat recovery, ventilation, fire safety, electrical, and HVAC systems for both existing and new data centre buildings.
The Mäntsälä facility is a key site for Nebius, an Amsterdam-based AI infrastructure provider. The expansion includes extending the current building and constructing two new data centre facilities, bringing total capacity to 75 MW. Caverion will supply liquid cooling to complement existing air systems, along with fire alarm and suppression, smoke extraction, and integrated energy systems. The project began in April 2025 and is set for completion in early 2026.
The site leverages environmental technologies including free cooling and district heat recovery. Currently, it recovers around 20,000 MWh annually—enough to heat about 2,500 Finnish homes. This volume is expected to increase with the expansion, contributing to reduced emissions from district heating.
“At Caverion, we are committed to similar high sustainability principles as those adopted by Nebius. This assignment is very important to us and speaks for Caverion's expertise in managing large-scale contracts and delivering high-quality technical solutions. We are proud to support Nebius in building highly performant, energy-efficient AI infrastructure in Finland,” said Ville Tamminen, CEO of Caverion Finland, EVP.
“Data centres and critical infrastructure are an important part of Assemblin Caverion Group’s strategy. Our position in the market is strong and we are pleased to support global infrastructure customers such as Nebius with our specialised capabilities and broad service delivery,” added Jacob Götzsche, Executive Chairman of the Board, Assemblin Caverion Group.
“The expansion of the Mäntsälä site is a strategically important part of our global AI infrastructure build-out, and will enable us to better serve growing demand from AI builders globally. We are pleased to count on Caverion’s expertise and multi-technical competence in ensuring timely, high-quality delivery,” said Andrey Korolenko, Chief Product and Infrastructure Officer at Nebius.