September saw the inauguration of Google’s data centre in Waltham Cross. The announcement was closely followed by Equinix’s acquisition of DC01UK’s South Mimms data centre, and Ark’s planning application to redevelop a site in Watford. 

Last year, the UK Government designated data centres as Critical National Infrastructure (CNI) – aiming to protect critical digital assets, minimise disruptions during cyber-attacks, adverse weather and outages, and position the country as a prime location for investment. 

Hertfordshire is poised to become a strategic digital hub for the UK, bolstered by the strength of its existing infrastructure - including Letchmore Heath substation and extensive national and international fibre routes, and its proximity to London, one of Europe’s leading data centre hubs. 

Several major projects are underway and approved for development: 

Waltham Cross, Broxbourne 

Google announced in September the inauguration of its data centre in Waltham Cross. 

• Part of a two-year £5 billion investment to meet the growing demand of Google’s AI services such as Google Cloud, Workspace, Search and Maps. 
• The project encompasses Google DeepMind with its cutting-edge advancements for AI in science and healthcare. 
• Projected to create 8,250 UK jobs annually, further developing the country’s AI economy. 
• Partnering with Shell as its 24/7 Carbon-Free Energy Manager in the UK, ensuring responsible infrastructure growth. 

South Mimms, Hertsmere 

DC01UK has sold its South Mimms data centre to Equinix, marking one of the largest global infrastructure deals in recent years, set to drive the next wave of cloud and AI innovation. 

• DC01UK will be one of Europe’s largest and most advanced data centre campuses, setting a new benchmark for excellence in digital infrastructure. 
• Projected investment value: £3.9 billion. 
• 85 acres ‘Hertfordshire campus’ offering 2 million sq. ft. of cutting-edge data centre space. 

Former Mercure Hotel, Watford 

Ark Data Centres has launched a consultation as it prepares for a planning application to redevelop vacant Mercure Hotel in Watford.  

• The company said: “Ark’s goal is to meet the ever-growing demand for data centre capacity in a way that provides real benefits to the people and the community. 
• “The state-of-the-art data centre campus will be powered by 100 per cent renewable energy and create highly skilled jobs on-site with as well as further jobs in the area. 
• “The proposed development will be a best-in-class campus able to deploy a full suite of government, Enterprise, Cloud and AI workloads across Ark's diverse customer base which includes many of the most well-known and valuable tech companies in the world.” 
• The projected investment value is in excess of £2 billion creating an estimated 235 additional jobs. 

Other pipeline developments

In May 2025, former deputy prime minister, Angela Rayner, approved plans for a £1 billion facility by high-tech infrastructure developer Greystoke Land in Abbots Langley. The site, covering 904,168 sq. ft., is expected to generate 260 operational jobs, providing benefits nationwide through the storage and processing of business date. 

Outline planning approval has also been granted for 54,895 sq. ft. data centre in Hemel Hempstead for North Tree Investments. The redevelopment of a former Blue Box Storage site intends to provide digital infrastructure whilst creating new job opportunities and offering public realm improvements. 

These significant commitments from global technology leaders highlight the county’s appeal as a destination for high-value inward investment. It reflects the groundwork laid locally by public and private sector partners and builds on our efforts to establish thriving clusters in key growth sectors and opportunities for our SMEs. 
 
Learn more about Hertfordshire’s key investment propositions and opportunities:

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