(a) Within the residential planned unit development, all utilities, including telephone, television cable and electrical systems, shall be installed underground. Primary facilities providing service to the site of the residential planned unit development may be exempted from this subsection. Large transformers shall be placed on the ground and shall be contained within pad mounts, enclosures or vaults.

(b) The developer must provide landscaping with shrubs and plants to screen all utility facilities permitted above ground. The planning and zoning board may require that substations be screened by trees and shrubs or walls resembling a structure which is compatible with the design of the buildings within the residential planned unit development.