My field shelter perhaps is not you are looking for for but here it is:
I got my OH to hammer in the extra long fence posts 2 for each pallet then slide the pallet over them, mine is one and a half pallets high for one side of it but you could use 2 pallets to give it more height, perhaps that would still be too low for your horse?
I then covered it in garden windproofing (stapled it on)
Then layed rubber mats inside to keep down on mud.
You can see here how the pallets go over the fence posts
This is the side which is one and a half pallets high
This is a smaller one I made
These shelters are very very robust and manage to withstand our Shetland gales.
Ok its pretty makeshift but is good for someone on a budget and you could put a sheet of corragated iron on the top and secure it down.
Hi friesian80 , I must say , although i'm thinking of the more traditional type of shelter , this diy job looks pretty good , i have used the pallet and post trick to make boxes to hold my pooh pickings , but my ID is 15.3hh and hates the rain in his ears ( does great eeyore impression!) We live in a valley so we are not so exposed as you guys, it's more for the rain than the wind.