The purpose of this article is to provide minimum requirements for the protection of life, limb, health, property, safety, and welfare of the general public and the owners and occupants of limited density owner-built rural dwellings and appurtenant structures. It is also the expressed purpose of this article to conform the regulations regarding the construction and use of limited density, rural owner-built dwellings and appurtenant structures to the requirements of Article 1, Section 1, of the California State Constitution, and the statutes of the State of California which require the department to consider the uniform model codes and amendments thereto; and local conditions, among which are conditions of topography, geography and general development; and to provide for the health, safety and general welfare of the public in adopting building standards. Any section, subsection, sentence, clause, or phrase of this article if, for any reason, held to be unconstitutional, or contrary to California statutes, such ruling shall not affect the validity of the remaining portions of this article.