NTT NAV1B at Mahape is planned at 30.4 MW of critical IT load — about 45.6 MW of facility load at the operator’s own 1.5 ratio, which makes it roughly half of the announced 90 MW phase one. The capacity is not in doubt. The stage is. NTT’s facility page still says the building is launching in FY22, a target that expired four years ago. An April 2026 report says two more facilities, one of them 30.4 MW, are still expected to join. A 2025 market analysis lists NAV1A and NAV1B together as 60 MW operational. A directory listing gives it 577,576 square feet of floor — 44% more than NAV1A, for 1% more IT load. Four published answers to one question. This page keeps all four and counts zero, because a building that four sources disagree about is not live capacity.
1At a glance
2Counted as live before it is
This is the most consequential kind of bad record in a market dataset, and it is not a data entry error. It is a building that everybody has silently decided is finished.
| Source | What it says | Stage implied |
|---|---|---|
| NTT facility page | “NAV1B, supporting 30.4MW of IT load is launching FY22” | stale |
| Data Center Dynamics, Apr 2026 | two more facilities, 30.4 MW and 40 MW, are expected to join soon | not live |
| 2025 market analysis | NAV1A and NAV1B listed together as 60 MW operational | live |
| Facility directory listing | 30,400 kW critical power, 577,576 sq ft | no stage stated |
Two of those cannot both be true. The registry resolves this the only honest way: it records the capacity, records every stage claim, and counts nothing.
If NAV1B is live, NTT’s Mahape phase one is delivered and the campus is at 90 MW of its 150 MW plan.
If it is not, half of the announced phase one is missing and the campus stands at 45 MW — 30% of plan, four years after the schedule expired.
No public source settles it. Anyone quoting Mahape as a 90 MW operational campus is choosing the first answer without evidence.
330.4 MW is half of phase one
The number matters because of where it sits in the arithmetic, not because it is large.
| Measure | Value | Basis |
|---|---|---|
| NAV1B critical IT load | 30.4 MW | operator-stated |
| Implied facility load | 45.6 MW | 30.4 x 1.5, the ratio proved by NAV1A |
| Announced phase one | 90 MW | two buildings, May 2022 |
| NAV1B share of phase one | 50.7% | 45.6 of 90 |
| NAV1B share of campus plan | 30.4% | 45.6 of 150 |
| Campus plan without NAV1B | 104.4 MW | 74.4 MW delivered or building, plus the 150 plan |
Two things follow. First, the 30.4 MW figure is twelve times NTT’s entire Vikhroli pair and 2.4 times its Mumbai 5 building. It is not a small phase. Second, the campus plan cannot be reached without it: remove NAV1B and 30% of the 150 MW disappears.
Which is why the stale schedule matters commercially. NTT’s most credible Navi Mumbai capacity number — 90 MW across two buildings — depends on a building it has not publicly confirmed since 2022, in a market where it has since announced a 500 MW campus at Airoli.
4The floor area problem
The one physical figure attached to NAV1B is a floor area, and it does not sit comfortably next to its sister building.
| Measure | NAV1A | NAV1B |
|---|---|---|
| Critical IT load | 30 MW | 30.4 MW |
| Floor area | 400,000 sq ft | 577,576 sq ft |
| IT load per 1,000 sq ft | 75 kW | 53 kW |
| Floor per MW of IT | 13,333 sq ft | 19,000 sq ft |
| Implied racks at 9 kW facility | 5,000 | about 5,067 |
| Stage | operational, 2022 | unverified |
A 44% larger building carrying 1% more IT load is either a different design — more halls, more plant, less dense — or a directory error. There is no operator figure to settle it.
The registry records the floor area as a listing, flags it, and does not use it to compute density. That is the whole discipline of this file: a number from a directory is not the same class of fact as a number from the operator, and mixing them is how a market report ends up 40% wrong.
Not how many megawatts, and not how many square feet, but how many cabinets at what kW — and is the building commissioning this year.
For NAV1B, nobody outside NTT can currently answer the second part.
5Procurement
6Limits and open questions
- Stage is genuinely unverified. The operator says FY22, one 2026 report says still to join, one 2025 analysis says operational. The registry counts nothing.
- 45.6 MW of facility load is derived from NAV1A’s 1.5 ratio, not published for this building.
- The 577,576 sq ft figure comes from a directory listing, not the operator, and conflicts in proportion with NAV1A’s published 400,000 sq ft.
- No rack count is published for NAV1B. The 5,000-cabinet figure is inferred from its sister building.
- The 104.4 MW figure in the table assumes the campus plan is facility load and the other phases are delivered as published.
- This is a short page on purpose. The public record on this building is a capacity, a schedule and a floor area. Padding it with anything else would be invention.
- What would close it. A commissioning date. That is the entire gap.
7Sources
Sources: NTT Global Data Centers Navi Mumbai facility page, Data Center Dynamics reporting on the NAV2 announcement of April 2026, DatacenterHawk listing for NAV1B, Datacentermap Navi Mumbai listings, and independent Mumbai market analysis.