You can build a pole barn that will be perfectly adequate for a lot less money than you can get a contractor to build one for you.  It is really not that difficult.  Another option you might think about are the car ports which are built on site by a team of traveling workmen.  They have a frame of square tubing and are roofed  with steel.  You can get the walls and ends enclosed for a nominal fee above the cost of the carport.  I had mine set on a three-block high foundation of concrete blocks.  The whole thing only cost me $1150, which was only slightly more than the materials would have cost had I decided to build it myself.  The work took only slightly more than one hour!

Marla

I have a carport.  We call it the "Horseport".  19' X 21' on 8' legs which puts the middle at about 15'.  North, South, and West ends inclosed.  Paid $1,300 for the building and built it off the ground 1' with $250 in chirt.

You could sketch these plans up on piece of graph very easily.

My loafing shed is 25 x 40  Since my zoning only allows a 1000 sf auxiliary building

I built mine as follows.

It has two main rooms. a 25 x 26  for the horses and a 25 x 14  I use to store hay in.

My three walls or three sides are poured concrete. Mainly because I built it back into a hill side and used the walls to retain the earth. If you are all above grade, just build it out of 2x4 framing. Also the concrete is pretty indestructible to the horses. They don't chew on.  If I bump it with the skid loader while scraping manure, the building doesn't collapse.  The concrete footings are 12" tall and the concrete walls are 8' tall.  From the air the concrete basically looks  like an "E" One 40 foot long back wall with three 25 foot long wing walls coming forward.

I bought a micro lam 40' long and installed it across the 3 wing walls. It is 12" tall and 3 1/2" thick.

I had the truss plant build trusses that are a 4/12 pitch. They have a 12" heel on the back to offset the 12" micro lam on the front. The bottom cords of the trusses are level and 1 foot higher than the top of the concrete walls or 9 feet above the ground. As an afterthought I wish I had made the ceilings height higher. I buy my hay in the large bales and stack it with hay forks on my skid loader. When stacking, I don't have much room to work with under a 9 foot ceiling. In fact in the hay room, I built the dirt up 1' higher to make sure no water runs in and spoils the hay. This build up reduces my headroom.  Concrete forms come in a standard 8' tall length and you pay high premium to get a 9 or 10 foot tall concrete wall.

Cover the trusses with 7/16? Wafer board. Cover the waferboard with ribbed steel roofing. 

The gable ends I covered with T-111 plywood.

I just put a gated fence panel in front of the section with the hay in it.

It really depends on what your budget is. How permanent you want it to be. What maintenance you are willing to put up with. What your grade or slope is. And how pleasing to the eye you want to make it.

I have put a divider about 4' high down the center of our loafing sheds. It keeps the alpha horse from forcing the low horse on the totem pole out of the shelter.

Brenda

http://www.cps.gov.on.ca/english/ss8000/index.html

 This website has all kinds of barn/building plans you can download.  The plans are in metric and standard.