A nonconforming use is a land use that was legal when it began but no longer complies with the current zoning ordinance. Because it was lawful when it started, it is "grandfathered" and may generally continue even though new rules would not allow it today. The doctrine balances an owner's vested rights against the community's goal of eventually phasing out incompatible uses.
How a nonconforming use works in Missouri
Zoning in Missouri is local. Cities and villages get their authority from Chapter 89 RSMo and counties from Chapter 64 RSMo, and each adopts its own ordinance. When an ordinance changes, a property that complied yesterday can fall out of compliance today. Rather than punish the owner for doing nothing wrong, the law lets the existing use continue.
That protection comes with limits, and stepping outside them can forfeit the right. Across Missouri ordinances, a nonconforming use usually:
- Cannot be expanded or enlarged beyond its existing scope.
- Cannot be changed to a different nonconforming use without approval.
- Can be lost if it is abandoned or discontinued, often after a defined period.
- May not be rebuilt if a nonconforming structure is substantially destroyed.
In short, grandfathering protects what was already there, not a bigger or different version of it, and the right survives only as long as the use genuinely continues.
Why it matters
For property owners, nonconforming status is what lets a lawful pre-existing use keep operating after the rules change. The city cannot force a lawful pre-existing use to shut down simply because it rewrote the ordinance. But the status is fragile: expanding, changing, or abandoning the use can quietly forfeit it, and the burden of proving the use lawfully existed and continued usually falls on the owner.
For buyers and lenders, a nonconforming property raises due-diligence questions. The status generally runs with the land and can pass to a buyer, but financing and closing often hinge on confirming the right exists and has not lapsed. Knowing whether a property is conforming or nonconforming directly affects what an owner can build, sell, or rebuild.
Frequently Asked Questions
Is a nonconforming use illegal?
No. A nonconforming use was lawful when it began and is generally allowed to continue, which is why it is called "grandfathered." It is treated differently from an illegal use, which never complied and is not protected. What the owner usually cannot do is freely expand, change, or abandon it.
Can a nonconforming use be expanded or changed?
Generally not without approval. The protection covers the existing use at its existing scope, so an owner usually cannot enlarge or intensify it and usually cannot switch it to a different nonconforming use. Growing or changing the use typically requires a variance or a rezoning under the local ordinance.
How is a nonconforming use lost?
Most often by abandonment or discontinuance, frequently after a period the ordinance defines, sometimes paired with an intent to abandon. It can also be lost when a nonconforming structure is destroyed beyond a threshold the ordinance sets, or when the owner expands or changes the use without permission.
Legal Disclaimer
This page provides general legal information about Missouri law and is not legal advice. It does not create an attorney-client relationship. Every situation depends on its own facts, deadlines, and documents; consult a qualified Missouri attorney before acting.