Not sure about the rules in other provinces but I do know from my yahoo chat groups that the rules for many US licensed home daycares is that the doors are to remain unlocked with the idea that athorities could enter unannounced at any time and so can parents meaning they have immediate access to their children. A locked door means a caregiver could be hiding something or doing something and make it right just before answering the door.

Now having said that my door is locked except during the drop off and pickups that happen close together but there is a gate between the children and the door that is closed at all times. I expect parents to ring the bell and me to answer it. I think it is rude just to walk in. This is my home first and a daycare second. The child belongs in my daycare but the parent is a guest in my home.