By default, when a user traces a home in step 1, Cool Calc estimates the default window area as a percentage of the above grade wall surface area. This approach is similiar to approaches taken by other ACCA Manual J software programs.
The user can either modify the default percentage or enable the override checkbox to enter the actual area (in sq-ft) of glass for each exposure.
One neat trick is to use the 3D view button on step 1 to rotate the house or view it from the street level. If birds-eye or street views are available, the user can often count the windows and multiply that by their approximate size to calculate the surface area facing each exposure.
Cool Calc also automatically assumes a u-value and shgc value of the glass based on local building code. This value can be overwritten if known, or the user can use the drop-down fields to calculate the u-value based on the type of windows found in the home (i.e. double pane, low-e, etc.).
For a full explanation of the window section view the 4 minute window video below which goes into further detail on each field contained in the window section.