Colt Data Centre Services has secured approval to invest £2.5 billion in three large-scale data centres at its Hayes Digital Park campus in west London.
The expansion, approved by Hillingdon Council, will add 97 MW of IT capacity to the site near Heathrow Airport, more than doubling its total capacity to 160 MW. Construction is slated to begin in mid-2026, with the first facility going live in early 2029.
The new facilities, designated London 6, 7, and 8, will operate entirely on renewable energy through a Power Purchase Agreement (PPA), Colt said. Under planning restrictions, backup generators can operate for a maximum of 15 hours annually. Grid connection via a high-voltage supply is scheduled for October 2027.
Colt positions the project as supporting the UK government’s industrial strategy by strengthening digital infrastructure for the AI economy, a focus of the current administration.
The company, which operates across Europe and Asia Pacific, plans to integrate a district heating network to channel waste heat from the data centres to local businesses and residential buildings. However, some studies have questioned the value of such schemes, noting they often require complicated infrastructure, and it can be challenging to make accurate projections on how much waste heat a data centre will produce in the future.
The campus will feature an Innovation Hub developed by Aecom, which Colt intends to “act as a base for innovation and community engagement,” with flexible space for future industrial use. Colt said it will provide value to the local community (if an industrial estate can be said to have one) by hosting events themed around culture, food, film, music, and literature.
Colt’s chief real estate officer Xavier Matagne claimed the development is an important milestone for the UK’s digital economy. “Data centers are a cornerstone of digital transformation. With this expansion, we can help power innovation, support the AI revolution, and contribute to the energy transition,” he said.
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