Place the confectioner’s sugar, meringue powder and water into a bowl and beat with an electric mixer for about 7 minutes until the mixture is smooth and when drizzled, stays on the surface for a few seconds. If you find that the icing is too thick, gradually add a few more drops of water. Place the icing into a piping bag fitted with a round tip.

Place a serving tray of your choice onto a flat surface. Pipe an “L” shape of icing onto the tray and place the back exterior wall of the house and one side exterior wall onto the icing. Hold in place for a few seconds, then pipe icing in the corner where the cookies meet. Add more icing if necessary for the cookies to stand upright on their own. Attach the other side exterior wall with more royal icing.

Attach the interior wall so that it creates two evenly-sized rooms. Allow the royal icing to fully set, about 1 hour.

To attach the roof, pipe plenty of royal icing onto the top edges of the exterior walls. Place one roof cookie at a time on top, so that the edges hang slightly over the exterior walls. Hold both roof cookies in place with one hand and pipe plenty of royal icing onto the area where the roof cookies meet. Hold in place for a few minutes until the roof feels secure. Then allow the icing to fully harden overnight.