Transparent windows

Some of my windows & glass doors are transparent, others aren't... I would like them all to be transparent, but I cannot seem to figure this out. All seem to be the same material (glass/standard). What am I missing?
Kim
HD Pro8

Here's a photo

For vector views there is a "check box" in "3D Settings" to allow or disallow "Opaque Windows from outside" which works except in the case of windows enclosed with a porch or deck. When I really want to have "Opaque Windows" on a porch or deck I apply an object that is opaque under all conditions on a custom layer or in the case of Pro where custom layers are not an option, a layer I am not using that I can independently turn on or off per view.

In Render (OpenGL) views the transparency of glass is adjustable via the "Render Tab" of the "Material Dialog" per material.

DJP

I believe sometimes it also matters on whether or not you have placed a window in a wall that has a deck or patio on the other side that hasn't been defined as an exterior room type.

I also recall that there are situations where using the same material for glass can display differently if the window is using it as the default as opposed to having it assigned that material separately.