Why not just have movable furniture?
you can purchase furnishings from carpenters & place them anywhere in the guild hall, also change the wallpaper, or to get around bandwidth & downloading issues, you can have the guild setup a package of custom textures for wall-paper & such in a separate folder in the PS directory, it would be a downloadable pack of textures & maybe 3D models (later...) there is the thing were guilds may mod the art to make there hall bigger... I wouldn\'t really want a guild Hall designed by someone else, that\'s why I think they should be customizable in-game. move furniture & change drapes.
I think there should be Buildings you can rent that only your guild can go into, like you get a key for joining the guild or somthing... there should be vacancies that you can go into & hang out... like abandoned buildings you could make a hang-out that you do not pay rent, however, if you do not someone may buy it & tare it down & you wouldn\'t have any say... like a band of bandit\'s secret hideout or somthing... there should be lots of potential buildings, I am guessing you would need @ least 1 for every 3 guilds @ least, & extra abandoned buildings you can hang out in...
That gives a new job, Locksmith, they can also pick locks maybe?
It\'s more realistic if there are bare buildings & you just have to put stuff in them. I\'m sure if someone made the inside of a building the devs would consider it already...
I just think there should be insides of buildings to start & guilds will naturally make some of them Guild-Halls.... :]