Here I give you the dimensions of the walls of the house:
1. BASE, ie the floor - 12cmx18cm
2. Large side walls -2 pieces - 10cmx16cm - on one wall draw a door and 2 windows.
3. Roof - 2 pcs - 8.5cmx18.5cm
4. Small walls (those with angle for the roof) - 2 pcs - 10cm (base) x10cm (walls) x7cm (side of the trowel that will hold the roof) - here at an optional walls you can also make a window.
Good luck with your work!