The time of year that you kid will determine to some extent where you kid. Nannies kidded in the colder part of winter or during periods of cold rains should have those kids inside to decrease the chance of losing kids.
During warmer times of the year, nannies can kid outside on pasture. Also, depending on your management system, you may need to place nannies and newborn kids in kidding pens for a few days. This allows the kids to identify their mother as well as the mother to identify kids. For single born kids this is not as important as multiple births. Keeping track of two and three kids can be difficult in large herds with large numbers of kids. Placing kids with their mother in kidding pens also allows you to keep a closer watch on the newborns to make sure they receive colostrum, the antibody rich first milk, and to make sure the nanny has milk and accepts the kids.
Kidding pens should be at least 4' X 4' to 5' X 5'. For large nannies, you may want larger pens. Plan on having one to two kidding pens for every 10 nannies. Nannies and kids should be placed in the pens for one to three days after the kids are born. Allow nannies to kid in a larger area outside the kidding pens to prevent the nanny from lying on the first kid as she gives birth to the second kid.