Repair, replace or leave it alone?
Not every old fence needs replacing. The practical response depends on whether the issue is cosmetic, repairable or genuinely hazardous.
Cosmetic
A weathered or unattractive fence that is still upright and functional is mainly an appearance issue. That is different from a fence that presents a safety or security problem.
Repairable
Loose boards, a damaged panel or an isolated failed post may justify repair without replacing the entire boundary.
Hazardous or insecure
A collapsing fence, exposed sharp timber, unstable posts or a large security gap should be treated more urgently. Record the condition with photographs and deal with the immediate risk before allowing a long-running ownership argument to delay sensible safety work.