Step 8: you'll need to add a blue line icing border around the outside of all the biscuits to stop the white flood icing from escaping. Let the icing dry for 10 minutes at room temperature, then flood the front and back panels with white flood icing.
Step 9: on your side and roof panels use your white and blue flood line icing to create a striped effect.
Step 10: put all the biscuits back onto the baking tray and pop in an oven heated to 50°c, or the lowest temperature your oven can go to.