A sleeping porch is a deck or balcony, sometimes screened or otherwise enclosed with screened windows, and furnished for sleeping in warmer months. They can be on ground level or on a higher storey and on any side of a home. A sleeping porch allows residents to sleep on a screened-in porch, avoiding warm convection currents from air and wall materials beneath or beside. Before affordable electric fans and/or air conditioning were installed, families often created such rooms, well-aired, where children would sleep during summer. The idea gained popularity in the early 1900s and became common in much of the United States.