What is overlay zoning and provide an example.

• A. Overlay zoning adds extra restrictions or allowances atop base zoning (e.g., historic preservation overlay).
• B. Overlay zoning replaces base zoning entirely with a single-use zoning.
• C. Overlay zoning is the same as base zoning and changes nothing.
• D. Overlay zoning is used to designate environmental cleanup zones.

Answer: (C)

Overlay zoning works by adding a secondary layer of rules on top of the base zoning district. The parcel stays within its base zoning in terms of allowed uses and densities, but the overlay imposes extra requirements or incentives that must be met alongside those base rules. For example, a historic preservation overlay might require review and approval for exterior changes to protect architectural character, even if the base zoning would otherwise allow certain uses or renovations. Similarly, a floodplain overlay could add building elevation or floodproofing standards on top of what the base zoning requires.

This layered approach means the overlay doesn’t replace the base zoning; it modifies or supplements it. That’s why overlay zoning’s purpose is to refine development outcomes without converting the land to a single-use regime.