| Primary value | 750 m² ((unsprinklered)) |
| Applies to | Office, mercantile, industrial occupancies |
| Exceptions | Sprinklered buildings → Doubled — 1500 m² |
| Storage / warehouse (unsprinklered) → 500 m² | |
| Compartment wall fire resistance → 2 hours min | |
| Basements (unsprinklered) → 750 m² max, regardless of occupancy type | |
| Single-storey buildings (no basement) → Permissible area increased by 50% | |
| Residential (Group A, unsprinklered) → 2500 m² | |
| Educational (Group B, unsprinklered) → 1500 m² | |
| Assembly (Group D, unsprinklered) → 1000 m² | |
| Institutional (Group E, unsprinklered) → 750 m² | |
| Measured as | Plan area between fire-rated compartmentation walls — separating large floors into smaller fire-controlled zones. |
| Source | NBC 2016 — Part 4, Clause 3.1.15 and Table 1 ✓ Verified |
Fire compartmentation is a key passive fire protection strategy in India. It divides large floor plates into smaller, manageable areas using fire-rated walls and floors. This contains a fire to its area of origin, limiting property damage and providing crucial time for occupants to evacuate and for the Fire Brigade to commence operations.
In Indian construction, compartment walls are typically constructed using 230 mm thick brick masonry or reinforced concrete (RCC), with all openings protected by fire-rated doors. Installing an automatic sprinkler system is a common design choice as it doubles the allowable compartment area, facilitating open-plan layouts.