Show / Hide House in 3D and butted glass window

[gecko3d]

Hi there
I am new to the forum, I have been using CA for a few months now.
I want to show a duplex-house in 3D in one picture, but then also have two separate shots with one house only.
Is there any possibility to show / hide one house to take a 3D shot with only one house on it ? And then do the same with the other house ?

secon question: how do I draw a butted window, frameless glass over a corner ? the link that is mentioned somewhere in the forum doesn't work anymore.

Thank you for your help
Nicole