Can you build an ADU in St. Louis, MO?

Allowed with site-plan review

The city adopted an ADU ordinance in July 2025, which is a positive signal, but the provided sources do not include the detailed standards or whether approvals are administrative in all cases.

Confidence: medium · Last researched May 2026

Accessory Dwelling Unit (ADU) rules

The city adopted Ordinance No. 72036 in July 2025 to define, permit, and regulate ADUs.

  • Detailed standards were not included in the provided source excerpt
  • Verify size, owner-occupancy, parking, location, and district applicability in the codified ordinance text

Related questions

Are ADUs allowed in St. Louis, MO?

The city adopted Ordinance No. 72036 in July 2025 to define, permit, and regulate ADUs.

Full investor analysis

You've seen the general rule. The full St. Louis, MO report shows which districts allow ADUs by-right vs. by special permit, the approval path and timeline, and the overlay/flood constraints that quietly kill ADU projects here. First town report is free.

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More about St. Louis, MO zoning

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This summary is AI-generated from public municipal sources and is not legal, engineering, or land-use advice. Always verify zoning with St. Louis, MO officials before making decisions.

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