Fletch
Striker
In what way mate , before i open a can of worms .Actually, it can have unforseen consequences these days...I know! If it becomes an issue, you will have to declare it if you come to sell your property, (as will your neighbour!)
Had a quick rough measurement . Very top end of our garden is raised 30inch , where we get last of the sun on evening , the post their side is 90inch (7.5ft/2.3m), for rest of our garden if he builds posts same height then they will be 120inch (10ft / 3m). Ive lived here 20 year and last thing wanted was a fall out with a neighbour