Design Rules🔥 Fire Safety

Refuge Area — Required Frequency in Tall Buildings

How often refuge floors / areas are required in high-rises
See also📖 NBC 2016🔗 NBC 2016🧮 RCC Design📒 Handbook Topic
Every 7
floors
above 24 m height
Every 7floorsrefuge area above 24 m heightREFUGE FREQUENCY
Primary valueEvery 7 floors (above 24 m height)
Applies toResidential, business, mercantile, assembly buildings > 24 m height
ExceptionsFirst refugeAt/above the floor at 24 m height
Refuge area≥ 15 m² OR 0.3 m² per person on the highest floor
VentilationRefuge open to atmosphere on at least one side
Alternate Refuge LocationA staircase lobby can serve as a refuge area if it is ≥ 15 m², open on one external side, and separated from the floor by a 2-hour fire-rated door. (Clause 4.12.3.2)
Calculation BasisThe area of 0.3 m² per person is calculated for the occupant load of the 'two consecutive floors' it serves, not just the highest floor. (Clause 4.12.3.1)
Frequency BasisThe requirement is height-based, not floor-based: first refuge above 24m, then subsequent refuges at vertical intervals not exceeding 15m. (Clause 4.12.3.1)
Prohibited UseThe refuge area shall be exclusively for the use of occupants as a temporary shelter and shall not be used for any other purpose. (Clause 4.12.3.3)
Measured asRefuge floors at every 7 floors or part thereof above 24 m. Each refuge sized for cumulative occupant load above.
SourceNBC 2016Part 4, Clause 4.12.3
✓ Verified
Why this matters

In densely occupied Indian high-rises, phased or total evacuation via stairs can be slow and challenging. Refuge areas provide a crucial, smoke-free safe space for occupants to await rescue or for the fire to be controlled. They are a key component of a 'defend-in-place' strategy, especially where external rescue access by fire services is limited.

Typical practice

Refuge areas are typically provided as open-sided terraces or balconies. To encourage their provision, most municipal corporations (like in Mumbai, Delhi, and Bengaluru) exempt them from Floor Area Ratio (FAR) calculations, making them a common feature in modern high-rise design.

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