We use the kitchen / family room which are open to each other. There are doors to close this area off from the rest of the house, and it has its own entrance, which also opens to the back yard. I love being on the main floor as opposed to a basement. I am the type of person who needs lots of natural light. The only time a dc child enters the rest of the home is to use the washroom (just upstairs in a slpit level). I really wanted clear boundaries between my home and my daycare space (which our family obviously also uses after hours). Nap time is done right in the room too. I have room-darkening curtains and pack n plays / nap mats. I usually read in the living room where I can hear everything in the family room.