Why this lands hardest on St. Louis subdivision trustees specifically

The St. Louis metropolitan area runs on an institution most of the country does not have: the recorded subdivision indenture, enforced by elected trustees. It is a nineteenth- and twentieth-century private-governance structure, and in Missouri it operates almost entirely on the instrument itself plus common law, because Missouri has no planned-community statute.

Those indentures are full of exactly the restrictions an ADU implicates: one single-family residence per lot; no more than one dwelling; minimum floor area; setbacks from side and rear lot lines; architectural approval by the trustees for any structure; prohibitions on outbuildings used as living quarters. A detached ADU three feet from a side lot line with no parking may be perfectly lawful under Ordinance 72036 and squarely contrary to the indenture.

That is not a prediction about how any particular dispute comes out, and we are not making one. It is the shape of the question that is now arriving, by right, across the city.

What a trustee board can do, in order

1. Read the indenture's own words before answering anyone. The operative phrases are usually specific: “one single private residence,” “one dwelling house,” “no structure other than one single-family dwelling and a private garage.” A board that responds to an ADU enquiry with “the indenture doesn't allow it” without quoting the clause is inviting the argument it will then lose.
2. Find out whether the indenture is severable, and whether it has a non-waiver clause. This is now the central question in Missouri covenant enforcement. In July 2026 the Southern District affirmed that a covenant scheme the grantor intended to be non-severable was waived and abandoned in its entirety, where every plaintiff was itself non-compliant. A year earlier the Eastern District held that an express non-waiver clause preserved enforcement despite inconsistent past enforcement. The drafting difference decided both cases.
3. Audit compliance before enforcing. If the subdivision already contains garage apartments, converted coach houses, or basement units let separately — and in the city of St. Louis a great many indenture subdivisions do — that history is evidence in a waiver defence. Know what it looks like before sending a violation letter.
4. Decide the policy question deliberately, at a meeting, on the record. Some boards will want to hold the restriction. Others will conclude that an ADU is a reasonable use in a city trying to add housing, and that enforcement is not worth the cost. Both are legitimate positions for a trustee board to take. Drifting into non-enforcement by inaction is the one option with no upside, because it produces the waiver record without the benefit of a decision.
5. If the board wants to permit ADUs on conditions, it probably needs an amendment, not a rule. A recorded “one dwelling” restriction is not something a trustee board can waive by policy. And amendment in a St. Louis-area indenture is often the hardest thing in the document: supermajorities of all lot owners, unreachable in a community where half the owners do not respond. The 2026 Missouri bill written specifically to fix that — the Declaration and Bylaws Modernization Act — died in committee.
6. Check whether the city requires review before an amendment can be recorded. Several St. Louis County municipalities do, issuing a letter of recordation only after planning-department review. Wildwood's published process requires the draft plus the preparing counsel's opinion of compliance. That is a county-municipality practice rather than a city of St. Louis one, but a board operating anywhere in the metro should ask before assembling consents.

The companion ordinances nobody mentioned

Ordinance 72036 did not arrive alone. Two related measures passed in the preceding weeks and they push the same direction:

Ordinance 72027 (Board Bill 42, Alderman Shane Cohn) — “An Ordinance recommended by the Planning Commission amending the Zoning Code to reform minimum lot size regulations for single-family and two-family dwelling units; and containing an emergency clause.” Passed 15 aye, 0 no; effective 11 July 2025. The municipal floor for lot area came down. The private minimum-lot and minimum-frontage covenants common in St. Louis indentures did not.

Ordinance 72025 (Board Bill 18, Alderwoman Daniela Velazquez) — rewrote residential occupancy load. The superseded text read “Occupancy load shall be limited by the most stringent of:” and the new text reads “Occupancy load shall be limited to:” followed by either a habitable-floor-area test or a sleeping-room-area test, plus: “Children under the age of six years old shall not count towards the occupancy load.” From both tests at their most restrictive to either test, with an exclusion for young children — a higher permitted occupancy on the same floor area. Effective 11 August 2025, and expressly not applying “to lawful occupancies existing at the time of the effective date of this Ordinance.”

For an association, that third one matters wherever an indenture or condominium declaration carries its own occupancy or single-family-occupancy cap. The municipal ceiling moved; the private one did not.

A note on the wider Missouri picture

St. Louis is not alone. Springfield's new land development code allows ADUs “in all single-family districts, subject to design and operation conditions,” and its citywide zoning map — approved 6 April 2026 — consolidated 25 districts to 14. Columbia, by contrast, still grants each detached ADU one conditional-use permit at a time, through a council bill and a public hearing.

Those three cities now sit at three different points on the same spectrum, and the covenant question is identical in all of them: the municipality decides what zoning permits, and the recorded instrument decides what the community permits.

One more thing in the zoning code worth knowing

St. Louis's planned-unit-development standards already contemplate trustee-maintained private drives: “All lots shall have access to a public or private street either directly or by way of a court or drive maintained under the jurisdiction of a trustee organization.” The city's code has recognised the trustee institution for a long time. What it has never done is subordinate a private covenant to a zoning permission, and section 26.04.040 says so.

What to watch next

The first contested ADU permit in an indenture subdivision. The city issues the permit; the trustees send the letter; and the question of whether a 1920s “one single private residence” covenant stops a 2026 backyard cottage gets litigated on that instrument's particular words and that subdivision's particular enforcement history. We have found no Missouri appellate decision on it yet.