Hi Specialmee.
I'll second what Dick said and add a bit also.
I've just been investigating hunting on school grounds here in Australia. School grounds are considered restricted grounds over here. The bottom line, is that not only should you get permission; make sure that it is writing!In Australia the burden of proof is on you to say that you have permission, and I would assume your laws would be similar on places that are restricted, as your laws come from the same foundations as ours.If we get caught over here detecting without permission and take any finds,then it is possible to be charged with brake, enter and steel(My lawyers advice)!
That would make for a very bad day.
This is not bad news by the way because:1)restricted places are harder to get into, you're more likely to make much better finds.
2)All you need to do is draw up a permission slip, that includes the details of who is to be detecting,where that person will be detecting,when that person will be detecting, and the signature of the person who has given permission(IT has to be the property owner or the manager of the property).The reason that this is good news, is that you will get to meet the person, and because you have taken the effort to approach them,They will tend to feel positive about encounter(re pore building) and give you permission.Getting them to sign the permission form, will ensure that their week end isn't going to be interrupted by a phone call from the police.
I have hunted on a school site once before on a Saturday and had half the school staff came through.It sure was nice not having to worry about being there.
Mick Evans.