Prepositions like an, auf, zwischen, vor and others can be used in a double sense: if you need to convey the idea of movement you need to use the accusative case along with them, while if the person/object stays still you use the dative.
But what happens if you have a composite complement (one which is built with more that a single piece)? For instance, let's say that you want to translate:
The children are walking in the street in front of the house
I'd like to know which case is correct for "in front of the house": the children move in street, so for this part of the sentence you'd use the accusative case, but what about the second part, where no idea of movement is directly implied? I then have two proposals:
Die Kinder gehen in die Straße vor das Haus (double accusative)
Die Kinder gehen in die Straße vor dem Haus (accusative and dative)
EDIT: the comments below outline all the possible cases. In this particular case, since the children are (and move) in the street, and this street is in front of the house, then the sentence number 2 is correct, as in case (6) in Eugene Seidel's comments.