Fire Compartment Area Lookup
Category, fire rating and sprinklers in; compartment limit out.
Inputs
Result
Formula
| Lookup | Table 5.3.1 by category × fire rating |
| High-rise | 1500 m² for grade I-II (grade III+ not allowed) |
| Low/multi | 2500 grade I-II; 1200 grade III; 600 grade IV |
| Basement | 500 m²; plant rooms 1000 m² |
| Sprinklers | add 100% to the tabulated value (×2) |
| Retail halls | 4000 high-rise / 10000 single or ground floor / 2000 basement, already sprinkled |
Multi-storey civil, grade II, fully sprinklered, general use: 2500 m² tabulated, doubled for sprinklers, so 5000 m² per compartment.
FAQ
Does a sprinkler system really double the compartment area?
Yes, but only with full protection - the whole compartment must be covered. Partial protection allows doubling only of the protected portion. The system must also be properly designed, accepted and maintained; shown on drawings but not commissioned does not count.
Why can a single-storey retail hall reach 10000 m²?
Because egress is easiest: people exit directly to grade, no stairs, short smoke travel. Even then it requires sprinklers, detection and non-combustible or hard-to-burn finishes together - all three. High-rise is capped at 4000 m² and basement at 2000 m², following the rising difficulty of escape.
Do fire shutters count the same as fire walls?
A fire wall is a true separation; shutters are a substitute with tight limits and cannot replace fire walls for compartmentation in general (atria and escalator openings are the recognised exceptions, subject to width and rating rules). A failed shutter means no separation, which is why width, integrity rating and interlock control are reviewed so closely.
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Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.