Bottom line: The 2025 Apollo carve-out split STACK’s Norway portfolio in two. Vaultica took the smaller urban colocation sites (see the separate Vaultica assessment); STACK kept the larger wholesale and hyperscale campuses — OSL03 at Fetsund and OSL04 at Holtskogen — and, per company registry evidence, may hold further sites this dataset doesn’t yet cover.
What checks out
- OSL03, Fetsund — a two-hectare campus, formerly DigiPlex Oslo Fetsund, four buildings: OSL03A (~10 MW, 4,200 m² IT space, the campus’s first building), OSL03B (operational, no separate capacity published), OSL03C (~3 MW, opened autumn 2020, “HYPERSTACK” design with ISO Class 8 fresh-air air handling), and OSL03D (~6 MW, ~1,800 m² white space, the newest building). 100% renewable hydro claimed.
- OSL04, Holtskogen — 18 MW across four buildings, previously in the dataset.
- Aggregate cross-check: STACK’s own current site states 40 MW combined across the two Oslo campuses. Subtracting OSL04’s 18 MW implies roughly 22 MW for OSL03, broadly consistent with the building-level figures here (10 + 3 + 6 = 19 MW, plus an unspecified OSL03B).
- STACK also separately operates a Copenhagen campus, COP02 (72 MW, 25 acres) — distinct from Vaultica’s much smaller COP01A, the same split pattern as Oslo.
Ownership — resolved, with one caveat
Traced through a Brønnøysund/Skatteetaten registry chain: Infrastructure Nordics 2 S.à.r.l (Luxembourg) → Infrastructure Nordics 3 AS → Infrastructure Nordics 4 AS → Infrastructure Norway I AS → seven Norwegian subsidiaries, including Si Osl 03.1, Si Osl 03.2, Si Osl 04, Si Osl 04.2, Si Osl 05.2, Si Osl 06, and Stack Infrastructure Norway AS. No OSL01 or OSL02 entity appears anywhere in this chain — consistent with those sites having genuinely moved to Vaultica rather than merely being rebranded in place.
The presumed current owner is Blue Owl Capital, via its January 2025 acquisition of IPI Partners. That is not independently confirmed at the level of this specific Luxembourg holding entity — a S.à.r.l.’s name (this one, LEI issued October 2021, consistent with the earlier IPI/DigiPlex era) would not necessarily change on a change of ultimate control. We’ve asked STACK directly to confirm.
The open question we are not resolving
Two registry entities — “Si Osl 05.2” and “Si Osl 06” — do not correspond to any site currently in this dataset. They may indicate additional Norwegian sites (OSL05, OSL06) that exist but haven’t been publicly documented, or they may be administrative/holding entities with no operating facility behind them. We are not creating pages for hypothetical sites. This is recorded here as the second question sent to STACK in right-of-reply.
No PUE figure is published for any STACK Norway site. No heat-reuse offtaker was found for OSL03 or OSL04 — a real contrast with OSL01/OSL02’s confirmed district-heating connection, now under Vaultica.
Confidence
Ownership chain to Blue Owl/IPI, via the registry: A (corroborated across multiple registry entities and each company’s own site). That the ultimate Luxembourg parent is currently Blue Owl-controlled specifically: B (presumed from acquisition timing, not independently confirmed at that entity level). OSL03 building-level capacity figures: C (third-party facility profiles; not re-confirmed on STACK’s current site, which gives only the campus-level aggregate). Right of reply was sent to STACK ([email protected]) on 22 August 2026, covering both the ownership-confirmation and the OSL05/OSL06 question; the response window is open until 4 September 2026.