Concrete floor strength is a big concern for hoists. 2 post needs to be bolted down. Consider getting the boltdown measurements to weld long nuts to a rebar frame. Also concrete wire comes in two gauges and you can have fibre added to the cement mix which adds strength. Consider underfloor beams which are trenches with rebar. Build the floor strong to support whatever. Also go over on the roof overhang. Yes the cost goes up quickly, but helps keep the sun off the walls and rain away from getting under the slab. Do not build too close to trees. Consider branches and roots as they grow. Another concern is storm damage and blowing a tree on the building.
