Generally it is not a problem when a building is crossing the outline of any landuse (residential, commercial, industrial etc.), but of course it is better when residential buildings are completely included in the residential area.
In your case you can simply expand the residential area to make the buildings fit inside. On the arial image you can even see at some places where the residential properties end and the forest begins (difference in colour). This may help you to draw the outline of the residential area, even without checking this on the ground. The only thing you should make sure that all of these buildings are residential (from the arial image I would definitely say they are).