In the opening credits of Married with Children we see an entire picture of the house. The front door is facing out towards the street. It is understood that Marcy lives right next door and in the adjacent yard. In several episodes members of the Bundy's look outside their front door and say that they can see Marcy doing things and that her house can be seen from there front door. Unless Marcy lived across the street this would not be possible and they can not look next door because the garage is in the way.