Well, as you say, it would have to be on the historic places register, because otherwise people would be just coming forward with some old building and wanting to get money for it.
Once you are on that register—and of course you can apply to be on that list if you aren't on it—I think you'd probably have to get three estimates of what it is going to cost to restore your building. Then there would be a certain percentage of that, but not the whole amount, that you could reclaim back. But that would only be after the building had been restored, and done so effectively, so that it wasn't butchered in the process, if you will.