Data centre campus, Hayes Bridge and Heathrow Interchange
Hillingdon's register records approval of hybrid application 78343/APP/2025/719: Phase 1 full permission and Phases 2 to 4 outline permission. The parent register gives 29 October 2025 as the decision date; Colt calls the October 2025 milestone a committee resolution to grant, while later council condition applications refer to permission dated 20 May 2026. The issued decision notice is needed to reconcile these dates. Construction commencement for London 6, 7 and 8 was not confirmed in the sources checked on 8 October 2026. Colt's 4 November 2025 release states 97 MW additional IT capacity and early-2029 first operation; its current undated project page states 98 MW and first-phase delivery in 2028. These conflicting operator figures and targets are retained as separate claims, not resolved estimates. The planning report's 250 MW is stated electrical demand, not IT load.
Key facts
- Operator / developer
- Colt Data Centre Services
- Location
- Hayes Bridge Retail Park and Heathrow Interchange, Uxbridge Road, Hayes, Hayes, UB4 0RH, London, United Kingdom
- Status
- Approved
- Facility type
- Data centre
- AI relevance
- Not stated
- Permanent jobs
- 232
Power & grid
- Published capacity
- 250 MW — Published electrical demandThe total electrical demand stated for the site, including cooling and losses.
- Share of UK tracked capacity
- 69.4% of published electrical demand
- Network operator
- SSEN (distribution); National Grid
- Grid connection date
- 1 October 2027
- Grid position
- Two connections stated: North Hyde 150MW (99MW Oct 2027, 51MW Oct 2029); Uxbridge Moor/Iver B 100MW from Nov 2029 (committee report)
- Power
- The Hillingdon planning committee report states that the development requires 250 MW of power, secured through two independent National Grid connections. Recorded as a stated electrical demand, not IT load. Checked 8 October 2026: Colt's dated 4 November 2025 announcement states 97 MW additional IT power for London 6, 7 and 8; its current undated project page states 98 MW (27 + 48 + 23 MW). Both describe the wider Hayes campus total as 160 MW, including other buildings. The 97/98 MW conflict is unresolved; it_capacity_mw remains null and neither claim is added to IT-load totals. The 250 MW planning figure remains separately recorded as electrical demand.
- Backup fuel
- Diesel
- On-site generation
- 73 diesel standby generators across phases (20 LON6, 38 LON7, 15 LON8); HVO proposed as an alternative where available. Total generator MW not stated.
Planning
- Council
- London Borough of Hillingdon
- Planning route
- Local planning (TCPA)
- Planning reference
- 78343/APP/2025/719
- Planning decision
- Approval recorded: Phase 1 full; Phases 2 to 4 outline. Date conflict: parent register 'Decided' 29 October 2025; Colt describes committee resolution to grant; later council applications cite permission dated 20 May 2026. Issued notice not retrieved to reconcile dates.
- Decision date
- 29 October 2025
- Green belt
- No
- Land area
- 4.2 ha
- Recorded objections
- 1
Benefits vs drawbacks
Benefits
S106: air quality £1,026,166 and carbon offset £1,830,527 (Phase 1), Healthy Streets £209,660; Innovation Hub as affordable workspace at peppercorn rents; construction training scheme; toucan crossing on Uxbridge Road.
Timeline
London Borough of Hillingdon approved the hybrid application (Phase 1 full, Phases 2 to 4 outline).
Source
Reality Score
Sources
- Planning application 78343/APP/2025/719 - Hybrid four-phase data centre campus, Hayes Bridge Retail Park and Heathrow Interchange, Uxbridge Road, Hayes
Primary record · London Borough of Hillingdon · 2025-10-29 · accessed 2026-08-12
- Planning Committee report: Hayes Bridge Retail Park and Heathrow Interchange (78343/APP/2025/719)
Secondary source · London Borough of Hillingdon · 2 October 2025
- Colt DCS plans three new data centers in Hayes, UK
Secondary source · DatacenterDynamics · October 2025
- Hayes expansion — resolution to grant; 97 MW additional IT; early 2029 target
Secondary source · Colt Data Centre Services (operator; primary statement) · 2025-11-04
- London 6, 7, 8 — undated page: 98 MW and 2028 first delivery; accessed 8 October 2026
Secondary source · Colt Data Centre Services (operator)
- Parent planning register 78343/APP/2025/719 — recorded approval and decision date
Secondary source · London Borough of Hillingdon
- Condition application 78343/APP/2026/1978 — references permission dated 20 May 2026; accessed 8 October 2026
Secondary source · London Borough of Hillingdon
Last verified
27 September 2026
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