This is a big room surrounded by a barrier. It can only be penitrated by someone of Espada level or higher. It has a secret invisable entrance only known to Stark's Fraccion. this baiier willset anyone on flames who isn't powerful enough that tries to get threw it.
The building does have a two story house with a living room and akitchen down stairs. It has a giant big room with a big bed where stark usually falls asleep on.