In calculating the solar heat gain, it does not seem to include the solar heat gains on each wall and roof element.
Maybe could create a Wall class as did with Window, and calculate the vertical and horizontal surface solar heat gains? or rename the Window class to Surface?

In calculating the solar heat gain, it does not seem to include the solar heat gains on each wall and roof element.
Maybe could create a Wall class as did with Window, and calculate the vertical and horizontal surface solar heat gains? or rename the Window class to Surface?