Koenig v. Aldrich (Trespass & Private Nuisance)

In Koenig v. Aldrich (2019AP242), the Wisconsin Court of Appeals (District III) held that intrusion into the immediate airspace of a property counted as trespass and that an L-shaped fence did not did not constitute a nuisance pursuant to WIS. STAT. § 844.10 (2017-18).


Koenig owns a parcel of property that checkerboards with three other parcels—in other words, the parcels are four squares with corners that meet at a point. Of the three other properties, the county owns the property diagonal and it is available to the public. The Aldriches own the two properties adjacent to Koenig’s.

Koenig used to access the diagonal public property by simply stepping over the checkerboard from his property to the public property. In the process, he passed through the air space of the Aldriches’ two properties.

The Aldriches erected an approximately eight-foot-high, L-shaped fence extending approximately ten feet in both directions at the subject corner. (It later dropped the fence to six feet.) Koenig sued to remove the fence, calling it a private nuisance. The Aldriches counter-sued and sought to restrain Koenig from trespassing on their property


Koenig argued that briefly passing over the airspace of someone else’s property should not amount to trespass, citing the statutory exception for airplanes passing over property. The Court of Appeals disagreed, holding the exception (and ensuing caselaw) inapplicable to Koenig’s actions.

The court also ruled against his private nuisance claim. WISCONSIN STAT. § 844.10 provides:

Any fence, hedge or other structure in the nature of a fence unnecessarily exceeding 6 feet in height, maliciously erected or maintained for the purpose of annoying the owners or occupants of adjoining property, shall be deemed a private nuisance…

The court held that the statue did not apply since the Aldriches dropped the fence to six feet, the fence “did not interfere with Koenig’s use or enjoyment of his own property,” and it was not evidently “maliciously erected or otherwise maintained to annoy Koenig.”