(A) As used in sections 153.50 to 153.52 of the Revised Code:

1. (1) "Construction manager at risk" has the same meaning as in section 9.33 of the Revised Code.
2. (2) "Design-assist services" means monitoring and assisting in the completion of the plans and specifications.
3. (3) "Design-assist firm" means a person capable of providing design-assist services.
4. (4) "Design-build firm" has the same meaning as in section 153.65 of the Revised Code.
5. (5) "General contracting" means constructing and managing an entire public improvement project, including the branches or classes of work specified in division (B) of this section, under the award of a single aggregate lump sum contract.
6. (6) "General contracting firm" means a person capable of performing general contracting.

(B) Except for contracts made with a construction manager at risk, with a design-build firm, or with a general contracting firm, an officer, board, or other authority of the state, a county, township, municipal corporation, or school district, or of any public institution belonging thereto, authorized to contract for the erection, repair, alteration, or rebuilding of a public building, institution, bridge, culvert, or improvement and required by law to advertise and receive bids for furnishing of materials and doing the work necessary for the erection thereof, shall require separate and distinct bids to be made for furnishing such materials or doing such work, or both, in their discretion, for each of the following branches or classes of work to be performed, and all work kindred thereto, entering into the improvement:

1. (1) Plumbing and gas fitting;
2. (2) Steam and hot-water heating, ventilating apparatus, and steam-power plant;
3. (3) Electrical equipment.