Join one side wall to one peaked wall. Pipe icing along the bottom of the side wall and along the bottom and inside of the peaked wall. Join the panels so that the side wall is positioned on the inside edge of the peaked wall. Press the sides together and attach to the base. Hold in place for several minutes until the icing begins to set.
Attach the other side wall and peaked wall in the same way.
Press together, and let dry at least one hour before going to the next step.
Pipe the icing along the roof angle of both peaked wall panels and along the top side walls. Pipe icing along one long side of one roof panel. (This will be the peak of the roof.) Position one roof section, so it meets the peaked wall and side wall edges.
Hold this half in place while you add the other roof section.
Adjust so that each side is evenly pitched and the center seam meets. Press and hold in place several minutes to allow the icing to set.
Let your house dry at least two to three hours before decorating.