http://officialfan.proboards.com/thread/475028/why-winslows-lock-doors?page=1

I mean, Urkel just walked in whenever he wanted. Think about all the property damage they could've avoided.

Because officer carl winslow felt sorry for him and told his entire family to keep the door open for steve urkel because if they lock the door he would get offended and think the winslows would not want to be his friends anymore and he would get depressed and try to find his roots in africa for 6 years lol