Drawing on tracked video footage with the grease pencil Fellow night workers,

I am trying to draw sketch like drawings of houses on to drone footage. I have used Syntheyes for planar tracking. Now I am trying to find the best way to draw in Blender. When using the grease pencil the lines will not attach to the planar tracking. Any suggestions on how to do this will be greatly appreciated. Attached picture is of the blocks where the drawings are suppose to be. The drawings are just lines, like a stick figure house.

Many thanks in advance 

//Hank
When you just want to add some paintings on the wall a simple image texture on a transparent background (e.g. created in Photoshop/GIMP) would do the job. If you would want to dynamically build up a drawing on the wall have a look at Blender's "Dynamic Paint"-system.