(a) By an order adopted and entered in the minutes of the commissioners court and after a notice is published in a newspaper of general circulation in the county, the commissioners court may adopt rules governing plats and subdivisions of land within the unincorporated area of the county to promote the health, safety, morals, or general welfare of the county and the safe, orderly, and healthful development of the unincorporated area of the county.
(b) Unless otherwise authorized by state law, a commissioners court shall not regulate under this section:
(1) the use of any building or property for business, industrial, residential, or other purposes;
(2) the bulk, height, or number of buildings constructed on a particular tract of land;
(3) the size of a building that can be constructed on a particular tract of land, including without limitation and restriction on the ratio of building floor space to the land square footage;
(4) the number of residential units that can be built per acre of land;
(5) a plat or subdivision in an adjoining county; or
(6) road access to a plat or subdivision in an adjoining county.