We advise Fortum in a collaboration project with Microsoft, whereby Fortum will capture the excess heat generated by a new data centre region to be built by Microsoft in the Helsinki metropolitan area. The data centres will use 100% emission-free electricity, and Fortum will transfer the clean heat from the server cooling process to homes, services, and business premises that are connected to its district heating system. This waste heat recycling concept from the data centre region will be the largest of its kind in the world.
18.3.2022
Fortum Joint Data Centre Project with Microsoft
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Neoen – Sale of data centre
We advised Neoen Renewables Finland Oy, part of the French Neoen Group, in its sale of a data centre project to a consortium consisting of international data centre developers and operators. This marked Neoen’s first data centre development project in Finland. Founded in 2008, Neoen is one of the world’s leading independent renewable energy producers. The company operates in 15 countries. It develops, finances, builds, owns, and operates solar power plants, wind farms, and battery storage systems. Neoen Group is owned by global alternative asset manager Brookfield Corporation.
Case published 17.9.2026
Nscale – Data centre project
Castrén & Snellman advised Nscale, a European AI infrastructure company, in connection with its planned data centre project in Harjavalta, Finland. The facility will be located in the Sievari industrial area. Castrén & Snellman’s advisory role encompassed the negotiation and execution of a site securing and development agreement (SSDA) with Fortum, as well as the preliminary land sale process for the Sievari site with the Town of Harjavalta. Under the SSDA, Fortum supports the advancement of Nscale’s project development, including grid connection design and permitting.
Case published 15.4.2026
Brookfield – EUR 1 billion holdco financing for DayOne Data Centers
We advised a leading global investment firm Brookfield, alongside a global sovereign wealth investor, on the Finnish law aspects of a EUR 1 billion holdco financing for DayOne Data Centers, a Singapore-headquartered developer and operator of hyperscale data centres. Structured as a seven-year secured holdco financing facility of €500 million, expandable to €1 billion – and secured by DayOne’s Finland platform – the financing will support the rollout of hyperscale developments in Lahti and Kouvola, providing nearly 300MW of planned capacity across Finland. The proceeds will also support DayOne’s global expansion across the EU and APAC, with flexibility to allocate to other key growth markets as required.
Case published 29.1.2026
Municipality of Tuusula – Data centre project
We are assisting the Municipality of Tuusula in the sale of land to funds managed by Blackstone, a global asset management company, for a data centre project. Currently, a preliminary agreement has been signed for the sale of the approximately 16.7 hectare site in Jokela, Tuusula. In October 2025, the Municipal Council of Tuusula approved zoning amendments that enable the construction of a data centre campus in the Vallunlenkki zoning area. The preliminary agreement on the sale of the land and the approval of the zoning are the first steps in a process that would upon its implementation constitute a significant investment that supports employment and economic growth in Tuusula and its surroundings. The next phase, the environmental impact assessment, is planned to commence in early 2026. Blackstone owns QTS, one of the worlds’s fastest growing data centre platforms with more than 82 data centres in operation or under development across Europe and the United States.
Case published 4.12.2025