This chapter shall not affect or prevent:
(1) The practice of naval architecture, landscape architecture as authorized in chapter
18.96 RCW, engineering as authorized in chapter
18.43 RCW, or the provision of space planning or interior design services not affecting public health or safety;
(2) Drafters, clerks, project managers, superintendents, and other employees of architects from acting under the instructions, control, or supervision of an architect;
(3) The construction, alteration, or supervision of construction of buildings or structures by contractors registered under chapter
18.27 RCW or superintendents employed by contractors or the preparation of shop drawings in connection therewith;
(4) Owners or contractors registered under chapter
18.27 RCW from engaging persons who are not architects to observe and supervise construction of a project;
(5) Any person from doing design work including preparing construction contract documents and administration of the construction contract for the erection, enlargement, repair, or alteration of a structure or any appurtenance to a structure regardless of size, if the structure is to be used for a residential building of up to and including four dwelling units or a farm building or is a structure used in connection with or auxiliary to such residential building or farm building such as a garage, barn, shed, or shelter for animals or machinery;
(6) Except as otherwise provided in this section, any person from doing design work including preparing construction contract documents and administering the contract for construction, erection, enlargement, alteration, or repairs of or to a building of any occupancy up to a total building size of four thousand square feet; or
(7) Any person from doing design work, including preparing construction contract documents and administration of the contract, for alteration of or repairs to a building where the project size is not more than four thousand square feet in a building greater than four thousand square feet and when the work contemplated by the design does not affect the life safety or structural systems of the building. The combined square footage of simultaneous projects allowed under this subsection (7) may not exceed four thousand square feet.