UK operator Ark Data Centres is planning a new data center development outside London in Watford.

The Watford Observer reports that Ark Data Centres has launched a consultation as it prepares a planning application to redevelop the vacant Mercure Hotel with Hertsmere Borough Council.

Ark has set up a dedicated website for the planned £2 billion ($2.6bn) development. On Ark’s main website, the company lists the former Mercure Hotel site as its planned Elstree campus.

The 200MW site could reportedly host up to six two-to-three-story data centers. Construction could start in 2026, with the first building launching in 2029. The company claims it will be the largest data center campus in Europe.

The company said: “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.”

BisNow reports the site was previously bought by DC01UK (a company owned by property firm Griggs Homes and Chiltern Green Energy) in 2020. The owners originally planned a large logistics development, and also put in a 120MW power reservation at the nearby substation in Elstree.

In 2021, Regen Properties LLP (a partnership between Griggs Homes and First Urban) was granted approval for a development totaling five warehouses. The hotel closed around 2022, but work on the redevelopment project never started.

After holding talks with a hyperscale data center occupier that ultimately came to nothing, DC01UK sold the site and its power allocation to Ark Data Centres. This week, DC01UK announced the sale of a development site outside London to Equinix.

Founded in 2005, Ark has 27 data centers across nine sites in operation or development across the UK and Belgium, totaling more than 560MW.

It operates data center campuses at Cody Park in Farnborough, Meridian Park in north London, and Spring Park in Wiltshire’s Corsham, with a number of projects under development, including Union Park and Alliance Park in west London.

Ark (not to be confused with the US operator of the same name that was formerly known as Involta) serves a number of UK government departments and agencies, and also has a joint venture with the Cabinet Office called Crown Hosting to provide colocation services to public sector bodies and government departments.

Elliott acquired Ark Data Centres in 2012, with European real estate investor Revcap retaining a minority stake in the unit.