This recipe includes how to cut out pattern pieces to make a gingerbread house 3 X 5 inches and 5 1/2 inches tall.
In a large bowl, cream together the butter, brown sugar, molasses, ginger, cinnamon, cloves and baking soda until smooth. Blend in the flour, xanthan gum, oil and water to make a stiff dough. Chill for at least 30 minutes until firm.
Cut out the following patterns for the gingerbread house (I used a new manilla folder for these pattern pieces): 2 rectangles 3 X 5 inches for the front and back, 2 rectangles 3 X 5 1/2 inches for the roof; 2 pieces for the end of the house 3 inches wide at the base and 3 inches to the roof line, then slanted to a peak 5 1/2 inches from the bottom. For entryway: 4 smaller rectangles, 1 1/2 inches X 1 inch for sides and roof of entryway; 1 piece 2 inches at the base and 1 1/2 inches to the roof line and slanted to a peak 2 1/2 inches from bottom for the front of the entryway. The blog has a pdf for the patterns.
Preheat oven to 375 degrees f. Set out 2 baking sheets.
Roll half of gingerbread dough on a piece of parchment that will fit baking sheet to about 1/4 inch thick. Align pattern pieces to see how many you can get on that half of dough. With second half of dough, again roll out on parchment to about 1/4 inch thick. Check that you can get the remaining pieces on this half. Once you know you can cut out all the pieces, cut around each pattern with a sharp knife but leave the pieces (and excess) in place. Remove the patterns.
Bake at 375 degrees F for about 15 minutes, until dough feels firm.
Place patterns on top of the gingerbread again and trim shapes, cutting edges with a straight, sharp knife. Leave to cool on baking sheets.
Mix all of the ingredients together using an electric hand mixer until the icing is smooth. If thin, allow to stand at room temperature to thicken. Stir with a spoon when ready to use and scoop into a pastry bag with writing tip. If still too thin, add 1/4 cup more powdered sugar. Again let stand to thicken. When icing is thick but still can be pressed through the pastry bag, begin decorating the flat pieces with basic doors and windows. Allow sufficient time to set up--3 hours or so before assembling and finishing the roof and decorations.
Assemble the house by gluing front, back and sides together at corners using royal icing. Hold steady for a couple of minutes until icing starts to set. Check that corners are square so your house looks straight. At this point you may want to use icing to glue house to the plate or cake board you will display it on. Once these are dry attach the (undecorated) roof pieces. These may need to be braced until the icing sets. Continue decorating the house and roof. Makes one gingerbread house.