I have been looking at barns a bit lately and would like to put one up next year. Right now I am thinking a pole-type barn with just a roof overhead. Ideally I would like 4' concrete walls all around with steel posts anchored on top of that but I think I will probably just line the bottom 3-4' with treated T&G 2x6's. Anyway, from what I've been finding out ventilation is one of the biggest concerns in a confinement building which is why I probably won't go with solid walls. I really like the hoop buildings I've seen but the cost of a hoop building is more than putting up a roof of steel which I think would last longer.
A slatted building would be great but I don't think you want the cattle in them for too long of period or they may have foot problems. Also a slatted building would add quite a bit of cost. I would like to build a covered manure bunker and just push the manure out and stockpile it while the weather is nice and when it gets colder switch to a manure pack but I'm guessing that will be a future project.
I'm not sure if it is cool to promote another website - but if you go to NEWAGTALK and do a search in the 'Stock' section there are quite a few threads about confinement buildings.
Let me know your thoughts and ideas as I'm still in the research stage.