## Facts

- The City of Ladue enforced a one-family residential zoning ordinance defining “family” as “one or more persons related by blood, marriage or adoption, occupying a dwelling unit as an individual housekeeping organization.”
- Joan K. Horn and E. Terrence Jones, an unmarried couple, jointly purchased and occupied a single-family home in a one-family residential zone with Horn’s two children and Jones’s one child.
- Horn and Jones lived as a single housekeeping unit: they shared a bedroom, pooled household expenses through a joint checking account, ate and entertained together, and jointly disciplined the children.
- After an anonymous complaint, the city demanded that the occupants vacate on the ground that the household did not meet the ordinance’s definition of “family.”
- The city filed suit seeking to enjoin occupancy; defendants counterclaimed for a declaration that the ordinance was unconstitutional and sought fees and costs.
- The case was submitted on stipulated facts; the trial court entered a permanent injunction for the city and dismissed the counterclaim, with enforcement stayed pending appeal.

## Issues

1. Whether limiting “family” in a one-family residential district to persons related by blood, marriage, or adoption is a valid exercise of municipal police power or is arbitrary and unreasonable in violation of due process.
2. Whether prohibiting an unmarried, unrelated but stable household from occupying a dwelling in a one-family district impermissibly burdens constitutional interests in privacy, association, or family autonomy.
3. Whether distinguishing between related and unrelated households for single-family zoning violates equal protection.
4. Whether the defendants’ household must be treated as a “functional family” within, or as a constitutionally required extension of, the ordinance’s definition.

## Decision

- The Missouri Court of Appeals affirmed the judgment.
- The court held the ordinance’s definition of “family” was a constitutional land-use regulation within the city’s police power.
- Applying rational basis review, the court found the classification between related and unrelated persons rationally related to legitimate zoning objectives.
- The court rejected defendants’ privacy, association, and equal protection challenges under both federal and state constitutions.
- The court refused to construe the ordinance to include a “functional family” of unrelated cohabitants, concluding that doing so would effectively amend the ordinance.
- Because defendants did not satisfy the definition of “family,” the permanent injunction and dismissal of the counterclaim were proper.

## Legal Principles

- Municipal zoning ordinances regulating residential use are upheld if they bear a rational relationship to legitimate governmental objectives within the police power.
- A one-family zoning ordinance may constitutionally define “family” by legal relationship (blood, marriage, adoption) and exclude unrelated cohabitants, absent a suspect classification or infringement of a recognized fundamental right triggering heightened scrutiny.
- Under rational basis review, a classification is valid if any reasonably conceivable facts could justify it.
- Courts generally will not rewrite an unambiguous zoning definition to adopt a “functional family” concept; policy changes to the definition are for the municipal legislative body.

## Conclusion

The court upheld Ladue’s single-family zoning ordinance limiting “family” to persons related by blood, marriage, or adoption, held the restriction rationally related to legitimate zoning goals, and affirmed injunctive relief barring an unmarried cohabiting household from occupying the residence in the one-family district.


City of Ladue v. Horn, 720 S.W.2d 745 (Mo. Ct. App. 1986)