The novel and very narrow issue presented is this: May a municipality lawfully require the owner of a private single-family residence who proposes to modify a portion of the interior of his residence, in an area not visible to the general public, to undergo the burden and expense of a review of his proposed project pursuant to the California Environmental Quality Act (CEQA)? The answer is "no." As we explain, although a municipality has very broad statutory discretion to grant or deny a required building permit, that authority does not extend to imposing CEQA review upon such an interior home project, even where the residence is listed as a city landmark and is located within an area registered as a state and a national historic district. What an owner plans to do to the private interior of his or her home does not implicate a significant adverse effect on the environment, which is the predicate for requiring CEQA review by a municipality.