Edifice is a safe word to describe a large structure or building in a fancy way. Understand that it does not describe the facing of a structure.
To be more precise, an edifice is a large, imposing structure; something out of the ordinary. A castle or a skyscraper is an edifice. A house or cottage, not so much, though you can describe a mansion as an edifice. A great city wall may also fit the description well.