Means of Escape

I ve research this topic many times, be it at the office. But each time i find there is much nuances that i have missed out.

Here, i will outline todays' discovery.
Exit requirement depends on 5 things:

1. Type of Use
2. Occupant Load
3. Floor Area (eg office/shop/warehouse if per floor <200m2 one exit staircase is enough, but also occupant load must be <50pax)
4. Travel Distance
5. Capacity of Exits

Type of Use & Occupant Load:
These two kinda go hand in hand. Starting from the approx office floor area of each plate: eg 3000 m2. Refer to Table 2.2 A, Type of use will indicate the occupant load. Office admin occupancy load is 10 m2/person. Approx 3000/10 = 300 pax

** In actual scenario, it will be the specific functional area(eg: admin, reception,shop, meeting room) divide by occupant load factor. Refer to occupancy load table.

Capacity of Exits:
This is tied to point 1 & 2. As From Table 2.2 A, office typology, the allowable escape through staircase per 500mm( unit width ) is 60pax. (Columns E & F).
Hence for approx OL of 300; at 60pax, 5 unit widths are needed. If each staircase is 1m, that means 2 unit widths, and so 2.5 staircase ~ 3 staircase needed.

This also means that the maximum permissable occupant load = 3(staircase) x 60(persons) x 2(unit widths) = 360pax

If mixed occupancy, most stringent measurement will be taken. Note best for each staircase to be of equivalent size, as difference will usually render the smaller one inadequate to provide for escape in event of fire.

Travel Distance:
Direct distance = 2/3 Travel distance.
Draw a straight line from most remote location to the the door of escape staircase. this DD should be 2/3 or less than TD(sprinkled or unsprinkled). This TD can be check from table 2.2A; one or 2 way.

Note max dead end of space to corridor door is 20m.