Ventilation requirements for a crawl space - February 7th 2002

Question from: Don
Courtenay, BC

Dear Shell,

Are their any National Building code regulations regarding the ventilation requirements for a crawl space? If not what is the trade rule of thumb?

Thanks, Don

Dear Don,

Crawlspace venting rule of thumb is 1 - 8" x 16" foundation vent for every 300 square feet or main floor area. The average home would have 2 vents on the front and back elevations and 1 vent on each side elevation.

It's just that easy.

Shell Busey