Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.
In a large bowl, whisk together the flour, brown sugar, ginger, cinnamon, cloves, baking soda, and salt.
In another bowl, beat the butter until creamy. Add molasses and egg, and beat until combined.
Gradually add the dry ingredients to the wet ingredients, mixing until a dough forms.
Divide the dough into two portions. Roll out each portion on a lightly floured surface to about ¼ inch thickness.
Cut out house shapes and transfer to the prepared baking sheets.
Bake for 10-15 minutes, or until edges are firm. Let cool completely.
For the royal icing, beat powdered sugar, meringue powder, and warm water until stiff peaks form.
Assemble the house using the royal icing as glue. Decorate as desired.