Which factor is NOT directly regulated by the Residential Building Code?

The reason landscaping features are not directly regulated by the Residential Building Code lies in the nature of building codes themselves. Building codes primarily focus on aspects of construction that ensure safety, structural integrity, and habitability of buildings. This includes regulations covering structural integrity, electrical safety, and plumbing standards, all of which are crucial for ensuring that a building is safe for occupancy and use.

Landscaping, while important for aesthetics and environmental considerations, does not directly affect the structural or safety aspects of a dwelling. Therefore, it falls outside the scope of what is typically governed by a building code, which is more concerned with elements that directly impact safety and compliance with design standards. As a result, landscaping features are generally guided by local zoning laws or other municipal regulations, rather than the Residential Building Code itself.