Hey, Jonathan! For the little garage panels and that one house part connected to them, what I did was I used Increment Snapping for the panels, first. Then with the building, I did the Active Element select as you showed, but changed snapping to Edge Snapping, scale+Y, and used the garage panel's edge to snap right to the grid. I did the opposite sides for the other side of the building. It worked nicely for me!
