2013 11 10: the pictured outdoor faucet is fed from a pipe that goes through the slab rather than through the wall. this is done to reduce the likelihood of air leaks.
the single pipe from the hose that feeds this outdoor faucet, feeds a second further reducing the opportunity for air leaks.
the faucet is constructed so that it drains water back into the ground when it shuts off. this prevents freezing in cold weather. it’s also very convenient.