Creating spirals in SketchUp is a straight-forward process after some initial calculations and planning. We show you how to do it in our SketchUp training courses.
First of all we need to establish the size of the spiral; in the example here we have created a 100-storey eco-city tower which is basically a huge spiral. We first created a circle of 24 segments and a radius of 40 meters. We then divided the circle into 8 segments like a pie, and deleted 7 of those segments, leaving us one slice of the pie.
Next we used the Push/Pull tool to extrude the slice upwards in the blue axis by 4 meters. This is basically one level of the building. And we convert this into a Component – this becomes the basic building block of the tower.
Then we rotated and copied the slice 7 times, thus completing the full pie once again. This time, however, the pie is made up of 8 identical components. The beauty of components is that when one is updated or modified, the rest are too. We then copy this pie upwards by 11 to give us the basis of the tower.
Now we select a component from each level, adding to the selection, giving us a stepped selection. Then we press Shift and select the lot again -this will select the inverse of the stepped set, and hit Delete. You should be left with a very basic spiral staircase.
It’s now simply a matter of entering one of the “steps” components  and modifying it to build the tower. Later add materials and shadows, and other components like people and vegetation. Then render the model in a program like Maxwell. Easy!
Many useful tips and techniques can be found at the SketchUp website. And see many examples of our own clients’ work on our Facebook page.
Other related SketchUp Blog Posts:

• SketchUp background
• SketchUp introduction
• SketchUp modeling
• SketchUp contours
• SketchUp workspace