Typical corncrib here in the midwest:
Two sides of crib about 6-7 feet wide, with a 8-12 foot or so isle down the middle for machinery. On top in the peak may be room for more corn (over the machinery area) or possibly bins for grain - oats, wheat, flax, barley. Often they are about 40 feet long.
So it looks like you have a nice building 40 feet by 24 feet, pretty sweet to use......
But if you look around, you realize they are built kinda odd, with the inside machinery tunnel walls supporting the roof. So you can't easily cut out the inside & have a full clear building - the roof would fall in. You need to do some serious re-trussing of the roof to make a nice clear-span building.
Also, most often those 7' crib sides are built up 8-12 inches higher than the middle machinery area. Removing & leveling this concrete takes some money too.
If you have to hire it done, & if the roof is already shot, many find on a dollar basis, level the old building & start over with a new one. You get more building for less money.
Me, I like to save the old buildings too.

It can be done, many have been converted. Just do your homework to make sure you get what you want for the cost.
A lot of them are turned into calf barns. put wire cattle panels down the sides, making the crib areas into raised calf pens, and store your feeding materials, sick pen, etc down the middle. Then you can leave the inner & outer wooden frame, tin the outside, and a pretty useable building for not much investment. Probably adaptable to other livestock as well.
If I missed the mark on the building you are starting with, sorry.
--->Paul