Proper installation of a new window requires
“The egress window sill cannot be more than 44 inches above the finished floor. The window, in the open position, must have an opening a minimum 20 inches wide and 24 inches high” a total of 5.7 sq ft [Examples are] Basically a 4 X 4 ft sliding window will make this and a single or double hung window must be at least 3 feet wide and 5 feet tall.”
We recommend casement windows that swing open the entire the window to minimize cost of the install. The codes in both Kootenai, ID and Spokane Wa, counties are nearly the same.

Source: Spokane City Doc
Additionally Document Spokane County Doc Code
Kootenai Code Doc