My daycare is in the basement with an entrance through the garage where the parents come in for drop off. Pick ups occur upstairs as that is where we are at the end of the day.
My kitchen is upstairs and that is where we eat. I and the kids like the change of scenery for lunch. Snacks are simple and served downstairs.
When we go outside we use the basement entrance/exit as it has more space to dress all in their winter gear. Warm weather we just leave by the front door.
Your non walkers will quickly learn to go up the stairs. I always follow behind just in case.
It is nice to have the seperate space so at the end of the day, the door is shut and family time begins.