193B—5.2 (544A) Exceptions. An architect registered in this state is required to perform professional architectural services for all buildings except those listed below. Persons who are not registered architects may perform planning and design services in connection with any of the following:
	 5.2(1) Detached residential buildings containing 12 or fewer family dwelling units of not more than three stories and outbuildings in connection with the buildings.
	 5.2(2) Buildings used primarily for agricultural purposes including grain elevators and feed mills.
	 5.2(3) Nonstructural alterations to existing buildings which do not change the use of a building:
	  a.   	 From any other use to a place of assembly of people or public gathering.
	  b.   	 From any other use to a place of residence not exempted by subrule 5.2(1).
	  c.   	 From an industrial or warehouse use to a commercial or office use not exempted by subrule 5.2(4).
	 5.2(4) Warehouses and commercial buildings not more than one story in height, and not exceeding 10,000 square feet in gross floor area; commercial buildings not more than two stories in height and not exceeding 6,000 square feet in gross floor area; and light industrial buildings.
	 5.2(5) Factory-built buildings which are not more than two stories in height and not exceeding 20,000 square feet in gross floor area or which are certified by a professional engineer registered under Iowa Code chapter 542B.
	 5.2(6) Churches and accessory buildings, whether attached or separate, not more than two stories in height and not exceeding 2,000 square feet in gross floor area.