Hi Rich,
In order for a building to be listed, it needs to be proposed at council chambers and signed off by the county councillors. Ideally it should be a property of architectural or social heritage. First off consult a good planning consultant & check out the history of the construction. Secondly, get your local councillors on your side.
Unfortunately many developers would be motivated by money!
If you are short of time & it is unlikely that the building would be granted a conservation order, your best recourse is to appeal any planning appliction through the normal channels.