How do you go about building and iconic building is a question I get asked often when this model is on display at shows. To be honest the answer is, “I don’t know”. Now this isn’t very helpful at all, but what I can say is, start! Sit down with your bricks (any colour will do) and start building.
I looked at a lot of reference material, the internet is a wonderful source of information and images, in the end I used a fictitious representation of the building from an advertising poster. The process started by working on the shape of the exterior of the building and getting the proportions right, this took several weeks with multiple iterations but once I was happy with the first level the rest were easy.