6 Tb. water
16 oz. powdered sugar
1. Beat meringue powder and water in medium bowl with electric mixer at low speed until stiff peaks form.
2. Beat in sugar at low speed until well blended. Beat at high speed until icing is very stiff. Cover icing with damp cloth to prevent icing from drying.
To Assemble (I do this the night before):
Spoon icing into a piping bag (or Ziploc bag) cut off tip or use a large circle tip (line of icing squeezed out should measure 1/8 to 1/4 inch thick).
Pipe royal icing onto the bottom and side edges of one piece, "gluing" bottom edge to platter or covered cardboard, stabilize with two heavy cups or canned goods. Attach remaining sides. Allow to dry (I also like to pipe a bead of royal icing along the seams on the inside to reinforce). When dry pipe royal icing onto top edges and attach roof. Allow house to completely dry.
Decorate with candies of your choice, attaching with royal icing...have fun!