My barn is a 24X60 shed row, with four 12X12 stalls, a 12X12 tack/feed room, and a 12X60 front overhang. The back of the barn faces north, and stalls have six foot gates on the inside, four foot gates on the back (for confining them in good weather) and solid sliding doors on the back as well, for bad weather/wind block. The barn is in a smaller, L-shaped paddock type area (we call it the barnyard, it’s a couple of acres in size and next to the house), that also opens to both pastures. With this set up and some cross-fencing, I can allow them access to the entire property (about 12 acres), or have them confined to one of the two pastures, a pasture and the barn, just the barnyard and barn, or a stall in the barn. Both pastures and the barnyard have a water trough, and each stall has a water bucket. They are all kept filled and fresh.
I leave the stalls with both gates secured open in good weather, but in bad I close them up. They still have room to gather under the overhang, if they choose to use it, and with the sliding back doors closed the front of the barn stays dry and windless. Both pastures also have plenty of trees, and they often just stay out under them instead. They are confined to their stalls for each feeding regardless, but are turned out once they are done. If the weather is really nasty, I’ll just leave them in their stalls with some hay until they can go out again.
The routine is always the same though, regardless of the season. They are out during the day, but confined to at least the barnyard at night - and that’s for safety’s sake. My property backs up to a curvy road, and there is a risk that a careless driver, going too fast around one of those curves, could lose control and plow right through my fence. It could happen in daylight as well, but I feel like the risk is even higher at night, since the road is completely dark. We also tend to have our worse storms at night and I have woken up to a tree down on the perimeter fence more than once. So, they come up at night, every night. Then in the morning, while they have their breakfast, the dogs and I check the fences. If all is well, which it normally is, then the gates are opened and the girls are free to roam about the place all day. If not, I can restrict them from getting to the damaged area, but still give them turn out, until the fence is fixed.
It’s a flexible system that works well for me, and I like letting the horses have as much turn out as possible. There are times when they might be comfortable staying up during the day (all the stalls have fans) and being out at night, but I doubt I would sleep! It’s just safer to have them closer to the house and out of (possible) harm’s way. When it’s hot, with the stalls open and the fans running, they often spend time dozing underneath them, coming and going as they please.