hmmm. . . I know the wizard didn't conjure the place for his own use -- or rather, to live in -- so the question would be whether he lived there or just regarded it as something to help him live in peace and quiet in his own home.

Given his peppery nature, I suspect it was the later.

Whether the courtyards really existed before and just are revealed now -- well, I wouldn't put it past him, but he didn't tell and won't appear in the story to tell, so it may prove moot.