I have a property that needs a total demo and renovation. It has not been lived in for about twenty years. 

It needs a new roof, I don't know the extent of electrical, I don't know the extent of plumbing, and personally, framing/walls is at the bottom of this list in my opinion. 

Yes, I am going to walk the property with a contractor to get their advice and bids. My plan is not to sell it. 

Which project should I do first with my money?