Bengaluru 4B is the middle of three identical buildings on NTT’s Devanahalli campus: 22.4 MW of critical IT load across seven data halls of 3.2 MW by campus design. Building A is live and dated. Building B has no published construction start, topping out or commissioning date. It is the building that matters most on this campus, because it is the one that takes delivery from 33% to 67% — and because it has to be financed against the leasing of a building that opened four months ago. Nothing else about it is uncertain. The module is known from Building A to the megawatt, the hall structure is published, and the 220 kV substation on site was sized for 100 MW of facility load. This is a five-section page because the public record is a capacity and a parent. The registry does not pad it.
1At a glance
2The middle third
The campus is three identical buildings, and the register of what has been published about them is short enough to reproduce in full.
| Building | Capacity | Halls | Published stage |
|---|---|---|---|
| Bengaluru 4A | 22.4 MW | 7 x 3.2 MW | live June 2026 |
| Bengaluru 4B | 22.4 MW | 7 x 3.2 MW by design | none |
| Bengaluru 4C | 22.4 MW | 7 x 3.2 MW by design | none |
That is the entire public record at building level. The campus announcement covers all three, the June 2026 launch covers one, and the other two are carried by the campus total.
This is not unusual and it is not a criticism of the operator. It is the normal state of Indian data centre capacity: a campus is announced once and delivered three times, and only the first delivery gets a press release.
It can say that Building B is 22.4 MW of critical IT with seven 3.2 MW halls, because the campus design says so and the operator has published the hall structure.
It cannot say whether Building B has broken ground. No source in the reviewed set does.
3What Building B adds
Two things follow from building it, and one of them is financial rather than technical.
| Measure | With Building A only | With Building B |
|---|---|---|
| Critical IT load live | 22.4 MW | 44.8 MW |
| Facility load live at 1.49 | about 33.4 MW | about 66.8 MW |
| Data halls live | up to 7 | up to 14 |
| Share of the campus delivered | 33% | 67% |
| Share of the 100 MW facility plan | 33% | 67% |
| Campus land used | 8.5 acres, unchanged | 8.5 acres, unchanged |
The financial point is the one that decides the timing. A three-building campus is normally financed one building at a time, and each building is financed against the leasing of the last. Building B exists when Building A is let, not when the market asks.
Building A is four months old at this record’s cutoff. If NTT follows the pattern it has followed everywhere else in this file — 76% of phase one leased at Airoli before the next buildings went up — then Building B is a 2027-2028 building rather than a 2026 one.
The technical point is easier. The site already has a dedicated 220 kV GIS substation sized for the 100 MW campus plan. Building B needs no new grid connection, which removes the slowest item on any Indian data centre schedule.
So the constraint on this building is demand, not infrastructure. That is a different and better position than most of the campuses in this registry, where the constraint is still the substation.
4Procurement
5Limits and open questions
- Stage is unverified. No construction, planning or commissioning evidence was found for Building B in the reviewed set.
- 22.4 MW counts zero here and must never be added to Building A’s 22.4 MW to claim 44.8 MW of live capacity.
- The seven-hall structure is a campus design figure published at the December 2025 commissioning milestone. It has not been independently confirmed for Building B.
- 33.4 MW of facility load is derived from the campus ratio of 1.49, not published for this building.
- No floor area, rack count, PUE or cost allocation for Building B specifically.
- This is a five-section page on purpose. A capacity, a sibling and an absence of stage is the whole public record.
6Sources
Sources: NTT Global Data Centers Bengaluru 4 campus page, NTT DATA announcement of 13 June 2026 covering Building A, press release material distributed in December 2025 describing the three buildings and seven 3.2 MW halls, and Data Center Dynamics reporting on the Bengaluru 4 campus.