The proposal for a £3.75bn hyperscale datacentre on Green Belt land near the South Mimms service station in Hertfordshire has moved forward, with planning documents now available. The project is being led by DC01UK, a joint venture formed in 2022 by Chiltern Green Energy and Griggs Homes.
While this is their first collaboration, Griggs Homes has prior experience in data center projects, having developed a facility in Bushey, Hertfordshire, which was sold to Ark Data Centres.
On September 9, 2024, DC01UK submitted outline planning permission to the Hertsmere Borough Council. The application seeks approval for the principle of using the land for a data center, with plans for up to 187,000 square meters of space, including office facilities, equipment, and a substation.
The final construction, however, would be undertaken by an “end-user,” who could adapt the design according to their specific needs. Potential operators, including colocation and hyperscale companies, have already been approached to take over the site.
The local planning process has received mixed reactions, with both objections and support. Concerns revolve around the impact on Green Belt land, biodiversity, and local traffic.
Plans for £3.75bn Hyperscale Datacentre Near South Mimms Move Forward, Facing Mixed Local Response
However, the project’s proponents argue it aligns with the UK government’s recent classification of data centers as critical national infrastructure (CNI), which could offer protections and encourage investment. The Department of Science, Innovation, and Technology has cited the South Mimms datacentre as an example of the type of development it aims to promote.
Despite government support, Hertsmere Borough Council leader Jeremy Newmark assured residents that local concerns would be considered. He expressed his personal backing for the project and announced plans for a public consultation to gather community feedback.
At the same time, the Labour government is exploring ways to streamline the approval process for data centers by classifying them as nationally significant infrastructure, which would bypass local council approvals.
The goal of these regulatory changes is to fast-track data center developments, particularly those on Green Belt land, which local councils have previously blocked. If adopted, these changes could make it easier for DC01UK’s project to move forward, particularly as they aim for a 2026 follow-up application.
For now, the project faces scrutiny from the local council, but the potential regulatory shift could significantly benefit large-scale data center developments in the UK.
The datacentre industry, while sensitive to local objections, highlights the economic benefits of such projects, emphasizing substantial investments into the UK economy. In many cases, data center developers also engage in community improvement projects, such as upgrading local electricity substations or reusing waste heat. However, DC01UK’s plans do not include heat reuse, although they emphasize the long-term economic benefits.
A report submitted by Stantec suggests the data center could create 100 jobs initially, doubling by 2031, with significant contributions to the local economy. Once operational, the entire facility is projected to support nearly 11,000 jobs and contribute over £900m in gross value added (GVA) annually.
Interest in the site has already emerged, with two colocation providers discussing pre-leasing the facility due to its strategic location with access to power and fibre networks.
As of now, the project’s fate lies in the hands of Hertsmere Borough Council and future regulatory developments. The outcome of the planning process, as well as potential changes in the government’s planning framework, will determine how the DC01UK project progresses, with the site’s readiness dependent on a planned power connection in 2029.
