1. Occupant Loads
FSE 101 – Fire Prevention

2. Occupant Loads
NFPA 101, 7.3

3. Occupant Load Factor (OLF)
How is it Formulated?
Analysis of similar occupancies deemed safe. These values have been adjusted over time to reflect modern usage of structures.
Why is it Necessary?
Allow a baseline for egress design
Protect structures from overcrowding
What are the Units?
Ft2/person. In other words, the OLF is the amount of space a person is allotted in the given occupancy.

4. Net and Gross Area Gross Net
The floor area within the inside perimeter of the outside walls of the building under consideration with no deduction for hallways, stairs, closets, thickness of interior walls, columns, or other features
Net
The floor area within the inside perimeter of the outside walls of the building under consideration with deductions for:
Hallways
Stairs
Closets
Thickness of Interior Walls
Columns,
Other Features

5. Area Formulas Rectangular Area Circular Area Triangular Area
A = (L)(W)
L=Length, W= width
Circular Area
A = πr2
π=3.14, r=radius
Triangular Area
A = 0.5(b)(h)
b=base, h=height

6. Nightclub Example Assembly Occupancy Overall dimensions – 75’x100’
Dance Floor – 30’x40’
Kitchen – 20’x50’
See next slide for Floorplan

8. Nightclub, Cont. Kitchen Dance Floor OLF = 100 ft2/person
Area = 20’x50’ = 1000 ft2
Occupant load = 1000/100 = 10 People
Dance Floor
OLF = 7ft2/person
Area = 30’x40’ = 1200 ft2
Occupant Load = 1200/7=171.4=172 People

9. Nightclub, Cont. Seating Area Total Load Bathrooms?
OLF = 15 ft2/person
Area = (75’x80’)-(30’x40’) = 4800 ft2
Occupant Load = 4800/15 = 320 People
Total Load
= 502 People
Bathrooms?

10. Bookstore Barnes and Noble Bookstore (street level)
Overall Dimensions – 300’ by 100’
Storage Area – 25’by 100’

11. Bookstore Solution Mercantile Area = 300x100-25x100 = 27,500 ft2
Load Factor = 30 ft2/person
Occupant Load = 27,500/30 = 917 people
Storage Area = 25x100 = 2500 ft2
Load Factor = 300 ft2/person
Occupant Load = 2500/300 = 8.3 people = 9 People
Total Occupant Load
= 926 People Total

12. Wendy’s Wendy’s 50 Fixed Seats Kitchen Area is 25’x50’
Waiting Area is 10’x20’

14. Wendy’s Solution Fixed Seats = 50 people Kitchen=(25)(50)=1250 ft2
Load Factor = 100 ft2/person
Occupant Load = 12.5 people = 13 people
Waiting=(10)(20)=200 ft2
Load Factor = 3 ft2/person
Occupant Load = people = 67 people
Total Occupant Load
= 130 People Total

15. QUESTIONS?