We spent day 4 trying to complete the the final model at a scale of 1:50. The structure was very time consuming due to the different angles. We also had some trouble getting the right heights which we only discovered once we had constructed both the floor plans and rooms.
We used foam board for the wall construction balsa wood, foam board, bubble wrap, and white plastic bags to resemble the structure. We ended up having to raise the external structure on the model so that it fitted over the rooms.