What term describes an unauthorized invasion of property, possibly affecting its value?

The term that describes an unauthorized invasion of property, potentially affecting its value, is encroachment. Encroachment occurs when a structure or object, such as a fence, building, or tree, extends beyond the property line onto neighboring land without permission. This invasion can lead to disputes between property owners and can indeed impact the affected property's value, as it may create legal complications or require corrective actions, such as removal or adjustment of the encroaching feature.

Understanding encroachment is crucial in real estate, as it relates to property rights and boundaries. It underscores the importance of conducting thorough due diligence, including surveys and property assessments, to avoid encroachments that could diminish a property's desirability or marketability.