Except as provided in article 43 of this chapter, no business shall be conducted or maintained in any building or upon any lot or premises, or upon any portion of either thereof, in zone R-4X1 except for the business of an apartment house. All property and buildings in zone R-4X1 hereby are limited to residential uses, except as otherwise provided in this article. (Ord. 01-O-2383, eff. 11-2-2001)