In 2006, we built a car port behind the workshop to house the tractor and store firewood. Many people keep their firewood uncovered outside, but we've found that the wood doesn't get completely dry this way. Covering the woodpile with a tarp is one option but this reduces the air circulation that helps with drying. More importantly, tarps disintegrate after a year or two (or maybe the cheap ones I buy), leading to tarp fibers getting into the pool if not promptly cleaned up.
The location of the outdoor furnace therefore was selected to be near the firewood to avoid unnecessary handling. This made the hot water line (InsulPex) to the house quite expensive because of the length of the run for the costly, insulated pipe. Although the pipe is well insulated (snow doesn't melt off from exposed line), we buried it several feet underground to minimize heat loss but mainly for aesthetics. Because the InsulPex pipe is 4" in diameter and extremely stiff, we had to bury it 4' deep at furnace to allow pipe to bend up into the bottom of the furnace.