Interesting and unique circumstances. First, a generic definition of adverse possession is insufficient for the purposes of any seriously contemplated legal action -- because the law differs in every U.S. jurisdiction. In California, (1) the elements necessary to establish title by adverse possession are: (1) tax payments, (2) actual possession which is (3) open and notorious, (4) continuous and uninterrupted for five years, (5) hostile and adverse to the true owner's title, and (6) under either color of title or claim of right. The party asserting title by adverse possession has the burden of proving affirmatively each one of these elements. (West v. Evans (1946) 29 Cal.2d 414, 417 [175 P.2d 219]; Mesnick v. Caton (1986) 183 Cal. App.3d 1248, 1258 [228 Cal. Rptr. 779]; Code Civ. Proc., § 325.) The above represents what your neighbor
must prove to avoid liability for the encroachment
. Typically, the tax payments are the difficult part of the proof, because if the tax assessor hasn't considered the encroachment area in the assessment of the property tax amount, then payment of property taxes on the non-encroaching portion of a structure does not pay the taxes on the encroaching area. This can raise some issues where witness testimony and records from the assessor's office may be required to prove/disprove the tax payments. In your circumstance, the neighbor has held the property for eight years, which means that the five-year requirement is satisfied. But, the tax issue probably is not, though I wouldn't take the County's word for what they've told you. The appraisers who work for the county are not lawyers, and they frequently make broad statements about tax and real property
law which are, for lack of a better phrase, "rubbish." Anyway, I don't know where you're located, but if you're looking for a lawyer to write a demand letter and attempt to negotiate in your behalf, I can send you a premium services invitation, and we can discuss the issue offline. I'll send the invite, and you can either accept or ignore, at your convenience. Otherwise, I hope I've answered your question. Please let me know if you require further clarification. And, please provide a positive feedback rating for my answer -- otherwise, the website retains your entire payment, and I receive nothing for my efforts in your behalf.Thanks again for using Justanswer!