Planning Departments will have informal discussions about what may or may not be allowed on any project whether you already own the land/building in question or not.

Found this out when I was in the market for a training field and found the Planning Department very helpful.

Had many issues with them after I bought the land mind, but that was down to one individual planner - a discussion with the lady's boss sorted it out and we did eventually get the change of use we were looking for

This is the problem with planning departments, people who have worked in them for a long time tend to get dellusions of grandier and also tend to put there promotion prospects before anything else so being pedantic about certain issues might show they are being dilligent but it doesn't help people who are hoping to buy a property and make it into something nice.