(a) The preliminary plans and outline specifications and the working plans and specifications for a project shall be prepared by:
(1) a private design professional selected and retained by the commission in accordance with Subchapter E; or
(2) unless the commission is required to retain a design professional under Subsection (b), the commission’s professional staff.
(b) The commission shall retain a private design professional for:
(1) a new construction project estimated to cost more than $100,000; or
(2) a new construction project for which the using agency requests a private design professional.

(c) The commission shall ensure that plans and specifications:
(1) are clear and complete;
(2) permit execution of the project with appropriate economy and efficiency; and
(3) conform with the requirements described by the previously prepared project analysis.
(d) The commission must approve plans and specifications before the using agency may accept or use them.