Design Load Formula & People At One Time Formula (PAOT)

Site Design Load Formula

Site Design Load Formula For Visitor Centres, Museums, Attractions, etc.

The following is an example of the site design load formula we use to identify the design load for a visitor centre, museum, historic site, etc.

In this example we will assume that 80% of the visitors to a historic site will use the visitor centre....

DL = VI x .80 x VS x VW

DL = Design load for the visitor Center
VI = Total visitation for the site (estimate)
VS = Percentage of visitation occurring during your peak season
VW = Percentage of peak season visitation occurring on weekend days or holidays
NW = Number of weekend days or holidays during the peak season


DL = 521,000 x .80 x.80 x .70 = 8,644


To determine people at one time (PAOT) expected in the center:

H x TR

DL = design load from above
H = number of hours of operations (8 used in this example)
TR = Turnover Rate (estimated 20 minutes length of visit or turnover of 3 visitors per hour)


PAOT = 8644 = 360 people at one time at your busiest time 8x3

So What Next?

So now you can make some assumptions...

360 visitors will need 25sq.ft. of floor space each as a MINIMUM for psychological carrying capacity.

That means this facility needs an exhibit room floor space of 9,000 square feet.

You can also now plan your visitor flow parameters and design dwell time...

This also means that you will need;

XXXX number of staff on duty
XXXX number of toilets
XXXX number of burgers in the cafe
XXXX number of car parking spaces
and so on...

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