When I put a front extension on our house and the building inspector visited to inspect the footings before filling them with concrete, he told me to stop work immediately as although I had planning permission, the useless architect that drew the plans didn’t mark a tree that was in our neighbours front garden. I should have known when I pointed out a mistake in the plans that showed footings 1m wide and 0.5m deep. He even pointed out a Rowan tree that was on the other side of the road and down a bit. He showed me a chart that had my neighbours type of tree (Leylandii) and my soil and and according to that chart, my footings should have been 2.2m deep! He suggested that I had a word with my neighbour and to make sure it wouldn’t be there when he came back to sign the extension off. My neighbour agreed when I asked him and I said I would replace it with another. I pulled his one up on the morning of the inspection and planted a new one that afternoon. It’s now as big as the house and it probably is within 5m of our house. Luckily I’ve never been asked about trees near to my property when I’ve bought house insurance.