Well if its small goats like Nigerian dwarfs then I would say about 40x40 pen would be good and a shelter also. Large dairy type goats need a little more space and a shelter also. I have 3 different kinds of goats and La Mancha are so laid back and the milk is wonderful too. I have Nigerians and alpines too. The Alpines milk is good too and so are the Nigerians. Good Luck in your choice...