We only need planners to stop the bloke next door doing something stupid except that the range of stupid things that people can do without permission is vast, almost as vast as the number of interesting things that people should do but the planners won't let them. You still see stone-clad semi-detached houses with the original brick next door.
The land adjacent to us is reputedly owned by a Mr Smith who has I think established a use as a lorry park because no-one has ever enforced against him and he does it at a very low level. His land is green belt and on the edge of town so his game is clearly to get residential planning permission in five, ten or twenty years. He doesn't annoy me and I don't know his address so it's let sleeping dogs lie.
If, however, you ASK for planning permission then they're all over you like a rash. And should permission be granted they invariably impose two conditions (at least). One is they withdraw the General Development Order consent (so you need permission to fart in the garden) and they always keep the right to approve materials. In our case they approved timber built stable with onduline roofing and then took ten weeks to approve the materials, at extra cost naturally. And yes it was wood.