Start by making cookie dough. Take butter, sugar in a bowl and cream well.
Add egg and molasses and mix well.
Add in flour, spice powders, salt, baking soda and fold into a soft dough.
Divide the dough into two portions. Wrap in plastic wrap and chill for 2 hours.
Cut out templates as per the link.
Roll the dough into thin sheets and cut out cookies as per template.
Place it in a parchment lined pan and bake for 15 to 18 mins. Remove and cool completely.
Now whip egg white and icing sugar till thick and fluffy. Add in water and whip till pipeable.
Decorate the house as per image and decorate it.