As long as your weather isn't too extreme one way or the other (hot or cold) you could get away with a three sided run in. If it is cold there put some kind of a floor in to keep it off of the ground. Make the doorway facing away from the north. Pigs love to make beds give it plenty of straw and change it out if it gets wet. They appreciate fresh straw at night to remake the nest. My friend uses a large igloo doghouse and they push the straw in front of the doorway to keep the wind out. She has a rubber flap across the opening.
During the summer it would be best to put the house in the shade. If not possible make sure it has a roof for shade and that you have big open spaces to keep it ventalated good. Pigs can't handle a lot of direct sun and heat. They can get nasty sunburns.
Your pig will appreciate having that much space to root around in and to make a wallow. The area will also stay a lot cleaner and be easier to keep clean. Given enough room, pigs are clean animals. It's when they are crowded or in too small of an area that they smell.
