Insurance companies are getting more and more unpleasant about loft hay storage. Some are even refusing to insure barns at all, if they have overhead hay storage. That's just how hazardous it is and how often it catches fire. Loft storages are hot, stuffy and put hay next to electric conduit. They encourage spontaneous combustion. There is a reason insurance companies don't like them.
Personally I hate overhead hay storage. It makes the air quality in the barn very poor.
Start a dialog with your insurance people right away. You want your insurance company to know you have a fire plan. Where to put the animals if there is a fire, how you will get water for the fire dept (pond? hydrant on road?) if there is a fire, and how you will stop the fire. Fire extinguishers, sprinkler system, fire alarms (most ordinary ones don't work in barns).
If I could, I would plan to put your hay and bedding in a separate building, which will make insurance happy. A metal building with a concrete floor where you can put pallets on the ground to get your hay off the floor so it won't rot or mold, is best. If not, plan on an OPEN area in your barn, not a tight stuffy corner or a stall. Plan to give it plenty of overhead space (most people can handle bales stacked 4 high or so). Plan how often you will run out of hay and how often you will need deliveries (or how you will get it to your barn - tiny loads in your truck bed on nice weather days only, etc). Be sure you can get emergency services and deliveries (from BIG trucks) back to your barn. Your stall kits, drain pipe, loads of gravel, construction materials, etc, all have to get back there - be sure you can get back there in bad weather too).
If you have a tiny hay or bedding storage area, you are going to pay the absolute top prices for these things and are going to have to take what you can get, and every time you get hay it will be slightly different and could sicken your animals. Plan for much more hay and bedding storage than you think you need.
Now is a good time to put a very, very firm limit on how many animals you will get. It's very tempting - put in a limited number of stalls and don't fall to the temptation to sacrifice more and more barn area to house more animals. Stick to your limit and maintain good hay and bedding storage. Don't crowd in more and more animals.
I'd NEVER put chickens and horses in the same area unless they were completely walled off from each other. You'll notice even on the oldest style farms, the chickens were in a completely separate building from the barn, unless there was no building at all for them.
I love my indoor washrack and have a hot water heater in the tack room and can pipe hot water to the washrack and extra lights high up on the wall. No, I don't do baths in cold weather, but it has been very, very useful to wash off wounds, for the farrier to work, and for the vet to work. My builder said not to have it drain out a wall because it would rot the wall, so the concrete in the wash rack is all sloped down slightly toward the drain. I have a rectangular 'box' underneath the drain in the wash rack, the bottom of the box is below the drain outlet, so the gunk settles to the bottom of the box and the drain keeps draining. I need to clean it out about once every three years.
Couldn't live without the concrete aisle. Keeps the dust down - a dirt aisle is miserable in the summer - dusty or damp and gets uneven, has to be filled in and graded all the time (my friend has one).
12X12 is a minimum stall size for horses, more is better if your 'midwestern winter' includes ice storms and days of being cooped up - my midwestern winter does. Consider having paddocks built next to the barn and having the stalls open out to the paddocks - but put an overhanging roof (high up) to keep rain from making the stall entrance into a mud pit. A fence that funnels the horses out away from the building helps keep them from gnawing up the building.
The most important thing is that the barn needs to be built on a pad that is raised up above the rest of the area - as far as possible. If you can build it at the top of a slope all the better.
Think, think, think and think about how your land lies, and where your pastures, paddocks and barn will drain to.
Your most important consideration farm wise should be drainage, how you will handle manure(usually the last thing people think about), and what your local laws are, and beyond the laws, what it takes to be a 'good neighbor' in your area. Don't rock back on your heels and say, 'I'm allowed to have animals, anyone who complains is an old meanie and I can ignore them'.
Start out from the beginning with the idea of being a super neighbor, not just a 'letter of the law' abiding one, a super, cooperative, considerate neighbor. That means manure, flies and odors are important. Unless you are surrounded by big animal farms, people will notice. And as silly as they may seem, they have rights, and they can also make your life a misery. Consider how you're going to deal with the manure and soiled bedding from all those animals? A pile of rotting pooh in the back forty? It might be right next to your neighbor's back yard or its runoff might drain onto their septic field or their porch. The county may have requirements for how you handle disposal of manure. It some areas, you have to rent a dumpster and pay to have it emptied. In other areas, you aren't allowed to spread manure on your land, so can't get rid of it that way. Even in the most unregulated areas, they won't like you accumulating a big pile of manure...EVEN IF you are officially classified as a farm.
I'd consider as very important your neighbors. If they all have horses, all neighbors on all sides, you MAY not have conflicts(except for differences of opinion on how to ride, feed, manage and handle horses, LOL!). But if you are ANYWHERE near a subdivision or are in a crowded area where there are lots of loose kids and dogs, shared driveways, poor fencing, consider the problems that could occur and plan your property to minimize them.
Research your deed and find out about any local covenants, right of ways or other easements to your property, such as rights of way the power company or utility company may have. Find out about land use, and if there are any buried tanks or debris or other things that are going to pop up when you do some construction.
Consider what your neighbors do for recreation - blow off bombs? Dive bomb your property with remote control airplanes? Let their fifty hound dogs loose on your back lot? They won't change when you get animals. If anything, all of a sudden you will start to notice just how annoying they actually are. If you have a small lot that just barely passes the zoning requirements for farm animals, think long and hard, about what it's going to be like to 'stock' your property.
No matter where you are, a perimeter fence is one of the chief things that makes 'good neighbors'. Keep your livestock contained - them getting loose on a neighbor's property is NOT a 'small deal', it is a big deal. Make sure that your animals will not be a nuisance and can't get loose. And life is better if you can keep everyone ELSE'S animals off your property too. Split rail is cheap but won't do the job unless it's much taller and is backed up with small mesh wire. Electric rope fences are popular with many people for the cheap initial price but take a lot of maintenance and the electric rope (or electric tape) needs to be replaced periodically.
Most people, when they decide to get horses, they first consider the size of barn, and the number of stalls.
In my way of thinking about it, the FIRST thing to consider is the lay of your land - where and how is the fall (change in elevation) on the land and what soil type is it. How and where does drainage go? Are there any storm drains or ditches by your road that handle drainage? How does the soil perk? What happens when there is a huge rainstorm? Where does water puddle and how long does it take to drain? What types of plants are there on the property? Joe Pie Weed and cattails? You may have some poorly draining areas. Moss? You may have some areas where the air is stagnant or there is little sun. Woods? Many woods soak up a lot of water and cutting them down for pasture can put a lot of runoff on your neighbor's land.
Know the local laws cold. Know if you need building permits, if you have setback requirements (meaning you can't build a building near your property line).
HAVE YOUR LAND SURVEYED. If you don't have visible boundary pins where your neighbors can see them any time they come walking out (and when you start clearing land, putting up fence and digging, you can BET they will be out there asking questions and wanting to know what's going on!), have a survey done and have them mark the boundaries, with extra pins if woods or topography mean a neighbor wouldn't be able to see exactly where the boundary is at any spot.
These are things Morton and the others will not take care of. You have to think about these things yourself. My neighbor has a worthless, unusable barn and she is boarding her horses for seven hundred bucks a piece a month, because she put the barn front door where every single drop of rainwater drains down to, and the barn floods every time it rains. He's got 20 foot high piles of bark chips that he thinks are going to solve the problem and which will NOT- they will only make it worse. You have to deal with drainage and runoff without breaking the law or trying to fight (or ignore) nature.
Think about where your drainage patterns are and where they go. If you plan to cut down trees consider what that will do to the drainage patterns.
Think seriously about how construction might affect the quality of runoff off your land and which neighbors will be affected by torrents of muddy water, even if just during your construction. Be prepared to surround construction areas with silt fences, and to seed them with a fast growing grass (dusting seed over the ground will not work, it has to be pushed into the ground and rolled in order to germinate) and straw them to improve runoff quality. Otherwise the water quality people will be at your door the second the trucks start rolling off your property covered in mud and leaving it on the road(or when neighbors start complaining their yard is full of brown water). Think about timing the construction to avoid periods of time in your area when there are heavy storms (usually early spring, august, some in fall in midwest).
Your barn will need to have a cleared area for construction. In the right weather, an excavator can 'build with clay' a pad to put your building on. Where ever you put your building, the top soil will have to be scraped off, and that topsoil will have to be dumped somewhere. Plan for how much topsoil is at the site for your building and how much will have to be removed. Depending on the soil in your area the topsoil could be up to 20 feet deep, you need to find out. And you may need to have clay brought in to build up a pad for the building and make up for the topsoil that has to be removed.
Your barn will have a roof that will collect a lot of water. It will be a big building. Think about where the water will go. Sixteen thousand gallons of water can come off a big roof in a rainstorm, where's it going to go? Best is gutters and downspouts that go down into pipe below the frost level (hopefully in trenches back filled with gravel) and drain the water to a pond or other suitable place for water runoff. Think about how much water can be picked up by the roof and get more downspouts than you think you need. If your property is flat you have to make a very, very serious plan for where all that water is going to go. You can't block the flow of drainage across your property and can't dump drainage onto other people's property, unless the natural flow of the drainage goes that way. But you may have to do something to slow the speed and velocity and volume of the water down if your buildings are going to make it much different from what it now is. Bioberms, evaporation ponds, water gardens, rain barrels, cachement tanks and space for temporary drainage ponds and other methods can slow down the water and encourage some to be absorbed while it's still on your property.
On the other hand, it's almost impossible to drive fence posts for paddocks and pastures when the ground is dry. In July, August and September you may have to pay extra to have the fencer dig holes instead of pound posts in or they all will crack kand break within a year or two.
I can't think of anything else right now!!!! LOL!!!!