how do you find out if another hostel is in the planning (in a particular city)?

So my friend and are in the early stages of our plan to possibly open up a hostel. We have some places in mind but my question is that its easy to know what hostels are already established there but how do you find out if another hostel is in in the planning stages there. I would hate to start the ball rolling to only find out later that another hostel was already in the works and open up before us. Thanks