Purchasing a house with an encroachment means that you have bought property that a neighboring property owner has encroached on. In this case, your ability to remove the encroachment or seek remedy against the neighbor varies depending on the timing of your awareness of the encroachment as well as other factors.
A property encroachment exists when a physical structure is partially or wholly built by a neighbor on your property. Land surveys are typically performed when new areas are developed and when properties are purchased. These surveys establish and confirm the legal boundaries of one property and help discern when one owner's physical structure encroaches within the legal bounds of another. Often, legal action is necessary for remedy.
Encroachments occur for many reasons. Rarely does a property owner simply build an addition onto his home knowingly encroaching on a neighboring property. If he plans to do so, he would likely get formal, written approval from the neighbor. Incorrect surveys, or mistakes made by owners and builders when physical structures are built are common. USLegal.com notes that fences, ditches, hedges and trees often form natural partitions between properties, but can also contribute to confusion over boundary lines.
When you purchase a house with an existing encroachment, your rights are based on a few key factors. Generally speaking, if the previous owner tolerated the encroachment and you purchased knowing it was there, you have essentially agreed to the presence of the encroachment. FindLaw notes that if you discover the encroachment later on, such as during a land survey, you may have more rights to remedy. The prominence of the encroachment is another consideration. Courts are more likely to decide in your favor when the encroachment is significant and impacting on your ability to use your property. A slight overhang from a roof may not weigh as heavily.
Specific remedies if you discover an encroachment vary. Ideally, you can communicate your concern about it to the neighbor and he will remove it if possible, sell the encroaching structure to you, buy that portion of your property or pay you a fee for its use. If simple communication is not effective, you may have to take the neighbor to court to seek action on the encroachment. This potentially leads to a long-term rift between you and your neighbor.