Single clear, frosted or laminated (excluding Low E) glazing typically has similar U & SHGC values. The attached WERS U & SHGC values demonstrate the U & SHGC values have minimal difference when changing the thickness of the glass or adding a lamination to the glass. Typically window manufactures do not provide a separate U & SHGC for a frosted obscure glass so always use default single clear for these types of windows if the glazing manufacturer is not know or not available in the BERS window library.
Opaque means that no light passes through so model as sheet metal.
For other glass you need to find out the U value and the SHGC and search for something that is similar in the default window database.
Please Note: the BERS glazing library is updated with a WERS window library database provided by CSIRO. Future plans is for each NatHERS software to directly link to the WERS library database, which will improve the glazing selection process.