Legal Question in Real Estate Law in Illinois

You say the fence is on the property line. OK. If so it is very possibly legal. The more difficult question is what is your house doing 8" away from the property line and how did that situation come to exist? And, if your house has been there for the requisite length of time you may have gained the right to what is called "adverse possession" of a minor portion of the neighbor's property, or minimally a "prescriptive easement" to gain access to that side of the house over a minimal portion of the neighbor's land, and now what the neighbor is trying to do is cut off your rights and making it your job to assert them through legal proceedings. Alternatively maybe the neighbor's fence is on the property line according to the neighbor's survey, but the survey is wrong. Point being there is a lot more here that would have to be looked at. I would look into it because if your house is only 8" away from the property line, that's very unusual and could cause problems down the line if and when you may want to sell it.