SFPE Discussions

Unprotected openings

Where Table 5.3/1, C/AS2 permits a maximum largest single unprotected opening of 6m2 on the external wall of an apartment firecell, in lieu of one 6m2 opening, is it permitted to have two 3m2 unprotected openings instead, less than 1.5m apart ?

The remainder of the wall (including the area between the unprotected openings) is fire rated and the combined area of the unprotected openings is within the maximum percentage of wall area permitted to be unprotected (Table 5.2a) .

Hi Nirav
Your total percentage of openings complies as per your statement as the enclosing rectangle combines both unprotected openings and the section of wall in between and therefore meet one criteria.
The other criteria is for the single largest opening, which in your case appears to be 3 m2. There will only ever be one opening that fits the definition of largest. If this meets the requirements them the wall should comply.