This building is extremely large, and has plenty of room for even a large Guild.
In all appearances, this Home seems to be extremely defensible (under what you would expect to be a normal siege). Notice the inner door and the half walls at the entryway (great for Archers). Unfortunately, UO does not follow normal siege mentality. Since exterior doors can not be picked or broken down, and interior doors don't lock, this is nothing more than window dressing.
This building differs from the castle in that there is not the open courtyard in the center. Quite frankly I have no idea why the 3 areas on the Main floor are unused. It would have been easy to have expanded the center room to use this wasted area.
Umm... This one is best viewed at 800 X 600. I didn't want to shrink the image more than 50%.