Adjusting height on Bay/box window

[redwood]

I watched David's video at Chief tutor.com. Great video. My problem is that I can't seem to resize the box window.

What I wish to have is the bay window not extending down to the ground. As it stands now it actually has a foundation. I want it to cantilever out.

I go into a elevation or 3d view and select the bay window and try to stretch the box up or down and it keeps jumping back the the original shape.

thanks