Summary
- Microsoft proposes one data centre building with data halls, offices, ancillary facilities, and a separately consented substation.
- The scheme replaces an expired outline permission for a larger mixed-use project that included affordable housing.
- Capacity, electrical demand, cooling, backup generation, and construction timing remain undisclosed ahead of the planning submission.
Microsoft is preparing a new data centre proposal for the former Langley Business Centre site near Slough, replacing an expired outline permission with a scheme focused solely on data centre use.
The current plan includes one data centre building containing technical halls, office space, and ancillary facilities. A substation will form part of the development but will be submitted through a separate planning application.
Microsoft held public consultation sessions on 14 and 15 July and is reviewing the feedback before lodging its proposal with Slough Borough Council. The company has not disclosed the intended IT load, gross electrical demand, construction programme, or number of planned data halls.
Consultation material indicates a building height of about 26.1 metres, rising to a maximum of 28.5 metres around the administration blocks. Existing boundary trees would be retained to help screen the development from nearby homes.
A revised use for an established site
The property previously received outline permission for a mixed scheme including up to 93,000 square metres of data centre space and 60 affordable homes. That permission has lapsed, and Microsoft said its proposal differs by concentrating on data centre development.
The earlier consent shows that the principle of substantial digital infrastructure on the site has already been examined, but it does not remove the need to assess the new design. Building layout, plant, access, noise, emissions, drainage, landscaping, and power infrastructure may all differ from the expired scheme.
Separating the substation into another application also divides the planning evidence across two processes. The data centre cannot operate without its electrical connection, while the substation’s footprint, equipment, access, and construction timetable will affect the deliverability of the main site.
The missing capacity figure is particularly important. Building area alone does not establish the operational scale of a modern data centre because rack densities, cooling technologies, electrical redundancy, and the proportion of space allocated to technical plant can vary widely.
Microsoft will need to explain the facility’s maximum demand, connection route, backup-power strategy, and any staging of the load. Cooling and water requirements will also determine the scale and arrangement of external plant, as well as the site’s noise and environmental performance.
Another project in the Slough availability zone
Langley sits inside the wider Slough data centre cluster, where operators benefit from dense fibre connectivity, proximity to London, established cloud architecture, and an experienced technical supply chain. Those advantages have also produced intense competition for suitable land and grid capacity.
The area continues to attract large developments and infrastructure financing. DataCentral recently reported how two Slough xScale facilities were placed behind long-dated secured debt, illustrating how operational data halls in the market are being treated as durable infrastructure collateral.
Microsoft’s proposal adds a different stage of the asset cycle: a pre-application project that must move through planning, power delivery, construction, fit-out, and commissioning before it can contribute usable cloud capacity.
The company already operates UK cloud regions and is developing additional data centre sites around the country. Each development still depends on local infrastructure rather than a national investment figure. Grid connection dates, substation delivery, contractor availability, and planning conditions will determine when capacity can enter service.
The Langley consultation has provided the first outline of the building but leaves most of the engineering case unpublished. The formal application will need to show how the site handles continuous electrical demand, heat rejection, generator testing, construction traffic, and its relationship with neighbouring homes and the nearby college.
Until those documents appear, the proposal is best treated as a defined site and building concept rather than committed capacity. Microsoft has identified where it wants to build and the broad form of the facility; the planning submission will reveal the load, plant, and delivery programme behind it.
