Correct, forget about it; I give up. Eight hours of my life have been spent, and I now have to recreate the sh3d file because it has vanished for what seems like the millionth time. sad .
Regarding building a sash window...

We are currently rebuilding our house - see plan below. It will be rendered but we are not sure if choosing sash windows will automatically make it traditional georgian style rather than a more modern look? would be grateful for any thoughts?