What is the opposite word of attic?

Opposite word of attic, which is top storage space of house under roof, is basement or cellar, which is bottom storage space of house below ground level, representing opposite vertical location in house. Attic is highest space, basement is lowest space, so they are natural opposites in architecture, similar to top versus bottom, high versus low. Other opposite concepts include ground floor versus attic, as ground floor is lowest living level while attic is highest. In terms of storage, attic is upper storage, basement is lower storage, so opposite. If thinking in terms of house structure, attic is under roof, basement is under house foundation, so opposite ends. Some may consider crawl space as opposite of attic, as both are low-height storage but attic is top crawl, basement crawl is bottom. In general language, opposite of attic is basement as most common antonym, as both are storage areas but at opposite extremes of house. For example, if you store seasonal decorations in attic at top, you might store tools and extra supplies in basement at bottom, like organizing Packout boxes in garage versus attic. So opposite word of attic is basement or cellar, representing lowest part of house versus highest part, providing opposite vertical location and storage function.