An ordinance amendment is defended on the record created before adoption, and that record is assembled by the drafter.
Purpose and findings. A statement of the problem, the evidence considered, and the connection between the regulation and the public health, safety and welfare. Where the regulation touches speech, religion, housing or interstate commerce, the findings should address the specific constitutional concern directly.
Definitions. Every operative term defined, and used consistently throughout. Most enforcement failures trace to an undefined term.
Standards, not discretion. Approval criteria must be ascertainable. Standards resting on compatibility or appropriateness alone are the most frequently invalidated.
Procedural provisions. Notice, hearing, decision deadlines, appeal rights, and the effect of failing to act within the period.
Nonconformities. How existing uses, structures and lots are treated, including expansion, discontinuance and destruction.
Transition. Applications pending at adoption, and any amortisation period.
Severability, so that invalidation of one provision does not take the ordinance with it.
Process. Planning commission review and recommendation, statutory notice, public hearing, and county or regional review where required. Skipping a statutory procedural step invalidates the amendment regardless of its content.