I think it is ideal if the door allows entry directly to the daycare playspace. One issue is making sure it is cleared as in not making parents make their way to a back door down an unshovelled sidewalk every morning. Many caregivers do that having parents enter via the side door or even through the garage which they open for dropoffs and pickups. The fact it is the same for everyone makes it simply the daycare door. A lot depends on the setup of the house and the daycare and where the doors lead to. Just make sure if you use a side or back door that you make the walk there nice with a few flowers in the summer and deiced and shovelled in the winter.