My model of the George Street Building

For the Cactus model, It will mostly be 'subtracting' objects from the building mass. To do the I will use the 'extrusion cut' feature. The shapes to be 'cut' from the building tend be predominently cubic. It appears that there are many extrustion elements in the model where and extrusion will occur from a surface that has been previously cut. I want to add my own style to it if this is acceptable, and try to create some organic features, so it maybe be different to the original and because of this it will maybe less accurate. The organic surfaces will be difficult because it seems that solidworks tends to work best with cubic shapes.