When I was growing up in China, every child learn the phrase " 坐北朝南 (meaning: south facting)" as an important criterion for selecting a site for home to built on and live in. This is particularly relevant since during the first half of the 20th century, China was still relatively poor and underdeveloped. Centralized home heating are rare. Thus having a southern exposure helps to keep the living quarters warm.  In 21 century American homes, this criterion is no longer important. However, "south facing" is still applicable. Here is a photo taken from our south facing window onto the courtyard of our retirement community complex. Note the snow covered ground in front of the north facing apartments and the no snow dividing line on the lawn days after the recent snow storm. It is our luck when we were admitted and our south facing apartment became available. Every idiom and well known phrase has its origin and rationale.