Put the sugar, syrup and butter in a saucepan. Bring to a simmer and bubble for 1-2 minutes, stirring until well combined. Cool for 10 minutes.
Tip the flour into a large bowl along with the spices and bicarbonate of soda. Add the cooled syrup mixture and the egg and stir together. Gently knead the mixture in the bowl until smooth.
Wrap the dough in cling film and chill in the fridge for at least 30 minutes.
Cut out the templates for each house – 1 roof piece, 1 side piece and 1 front/back piece. Line 2 baking sheets with baking paper. Roll out the dough approximately the thickness of a £1 coin on a floured surface and cut out the pieces with a sharp knife – you will need to cut 2 pieces with each template.
Cut out the door and 2 or 3 windows with a sharp knife but leave the pieces in place for baking
Bake in the oven for 10-12 minutes or until the gingerbread start to brown on the edges. Recut and remove the window and door pieces immediately with the knife and leave the gingerbread on the trays for 10 minutes. Transfer the gingerbread pieces to a cooling rack to crisp up.
Fit a piping bag with a No.2 piping tip and spoon in some royal icing.
Decorate the house fronts with the royal icing, pipe the windows and door and any architectural details. Leave the icing to harden for an hour or 2.
To construct the house, attach the 2 sides to the house front with royal icing, then attach the back panel.
When the icing has set you can attach the roof pieces. You may need to file them down with the grater to ensure a snug fit. Use folded up kitchen roll to support the first roof piece before attaching the next.
Decorate the roof by piping on tiles and a covering of snow!