Neb. Rev. Stat. § 71-5723: Neb. Rev. Stat. § 71-5723

Indoor area means an area enclosed by a floor, a ceiling, and walls on all sides that are continuous and solid except for closeable entry and exit doors and windows and in which less than twenty percent of the total wall area is permanently open to the outdoors. For walls in excess of eight feet in height, only the first eight feet shall be used in determining such percentage.