SoftBank Tomakomai AI Data Center · Tomakomai, Hokkaido, Japan
Last change recorded — · Last checked 2026-10-05
¥65bn first phase of 50 MW on a 700,000 m² site, expandable to 300 MW and reported as a possible 1 GW campus; ground broken April 2025. SoftBank's February 2026 update: construction about 60-70% complete, opening targeted in fiscal 2026 (year ending 2027-03-31). · source ● primary, confidence medium
Recorded readiness — 2 of 6 applicable milestones have a dated public record
Gate to first power — target 2026-12-31 (announced) · path: Grid supply · each step must finish its lead time before the target
0 of 3 required steps have a public date. Red = recorded date past the rule-based deadline · grey "no public date" = required step without a record · green = on record in time · context steps never colour.
| Step | Must finish by | Others did it | Known date | Status | Basis | |
|---|---|---|---|---|---|---|
| Site secured (context) | 2025-09-28 (15 mo before) | 13 mo before (n=26) | 2023-11-01 | context | Campus announced (reported) · ● | |
| Grid supply agreed | 2026-03-28 (9 mo before) | 7 mo before (n=11) | no public date | no public date · would need to be done by 2026-03-28 | No date on record | |
| Substation and lines energized | 2026-10-28 (2 mo before) | 15 mo after (n=1) | no public date | no public date · would need to be done by 2026-10-28 | No date on record | |
| Construction started (context) | 2024-12-28 (24 mo before) | 29 mo before (n=15) | 2025-04-01 | context | Construction start (reported) · ● | |
| Building ready for IT | 2026-12-28 (0 mo before) | 2 mo after (n=7) | no public date | no public date · would need to be done by 2026-12-28 | No date on record |
Lead-time assumptions
- Site secured 15 months before first power — Land under control and campus announced. Rarely binding; shown for context.
- Permits in hand 0 months before first power — Final air and siting permits. Operators often energize on standard or temporary authorisations and receive the major permit later; flagged only when the permit lands more than 6 months after first power or is missing for an on-site plant.
- Grid supply agreed 9 months before first power — Interconnection or large-load agreement approved. Observed median 7 months before first power; the physical works (substation, lines) run in parallel with construction.
- Substation and lines energized 2 months before first power — Utility delivery point live; final tests before the load is taken.
- New generation online 1 months before first power — Utility plant or on-site plant generating; needed just before energization when the grid cannot carry the load alone.
- Major equipment on site 6 months before first power — Turbines, transformers, switchgear delivered; installation and commissioning take the remaining months.
- Construction started 24 months before first power — Groundbreaking of the building that gives first power. Observed 4-26 months for recent AI campuses; Meta's redesigned campuses took 35-58.
- Building ready for IT 0 months before first power — First building ready for IT. 'Complete' or 'opened' is usually reported after first power; flagged only beyond 3 months.
- Full build-out complete -12 months before first power — All announced buildings operational. Comes after first power by design; context only.
- Water supply secured 12 months before first power — Water rights, municipal agreement or desalination contract in hand. Context only; one of the feasibility items.
- Financing closed 12 months before first power — Project financing, anchor lease or committed capital announced. Context only; not applicable when the owner is a hyperscaler building on its balance sheet.
Dated steps (from the sources; later dates are plans)
Build-out timeline (announced phases from public reporting; rows after today are plans)
Recorded fact No public date for grid supply agreed, substation and lines energized, building ready for it.
Calculated requirement Grid supply agreed must finish by 2026-03-28; no public date is on record for it. Under the current rule set the recorded dates plus their lead times give a first power no earlier than 2026-12-31 (on the target). This is a floor set by the record, not a forecast.
Sources: Inside SoftBank's next-generation AI data center in Hokkaido (SoftBank News, 2026-02-25)
Campus outside the Epoch AI dataset: facts from the public reporting linked above (tools/campuses.csv), coordinates hand-entered. Data retrieved 2026-10-05. Report a correction to contact@ailoadmap.com (campus id softbank-tomakomai-ai-data-center; include the row and a source link).