Once all parts of your house are baked and cooled (you can do this the day before), it is time to build your house. Fill a piping bag with royal icing. Pipe a thick line of icing on the bottom (base) edge of the first side wall. Stand side wall on your sturdy foundation, icing side down, 5cm in from the edge of the "garden". Hold for about 5 minutes to set; use tins from your cupboard to stabilise - one on each side of the wall - and hold it in place.
What should I use for a base?
A sturdy foundation is essential if you want to enjoy your house throughout the festive season. Use a heavy wooden cutting board or doubled-up pieces of sturdy cardboard. Cover with aluminium foil to make decorating easy.