ownership

Hello This is going to be a very bizarre question. A neighbour of mine was getting a gardener to replace a patio with a new one. The gardener was smashing up the slabs so put them in the back of his van. I asked the gardener if I can have the slabs. He send yes, he'll stack them up for me...

It's just curiosity on my part - do you need to have the permission of the owner to successfully apply for planning permission? it came up in conversation with a friend - a developer was applying for planning permission to redevelop a building, and the permission he was seeking included...