Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the flour, ginger, cinnamon, baking soda, and salt. Set aside.
In another bowl, beat the softened butter and brown sugar together using an electric mixer until light and fluffy.
Add the molasses and egg to the butter mixture and mix until well combined.
Gradually add the dry ingredients to the wet ingredients, mixing until the dough comes together.
Divide the dough into two portions. Roll out each portion on a floured surface to about ¼-inch thick.
Use gingerbread house templates to cut out the shapes (walls, roof, etc.) from the dough. Transfer the cutouts to a baking sheet lined with parchment paper.
Bake the gingerbread pieces in the preheated oven for 15-20 minutes or until firm. Let them cool completely on a cooling rack.
While the gingerbread cools, prepare the icing. In a mixing bowl, combine powdered sugar and water. Beat until smooth and thick enough to pipe.
Once the gingerbread is cool, begin assembling the house by applying a layer of icing to hold the walls together. Allow it to set for a few minutes.
After the walls are secure, add the roof pieces using icing as adhesive.
Decorate the gingerbread house using the icing and assorted candies, creating fun designs and patterns.
Allow the icing to dry completely before serving or displaying the gingerbread house.