1st April 2024

Spiral Observatory Tower Brief

Hi there,

I firstly want to thank you for buying this model, your support means a lot to me and I hope I won't let you down. But without further delay, let's get stuck in.


This spiral observatory tower is created after a wooden observation tower in Denmark. It's an impressive-looking tower with an interesting shape.

Image Credit: Denmark's spiral forest tower is finally open and it's spectacular - Lonely Planet

Its geometry and anatomy make it an ideal candidate for Grasshopper. You can read more about this tower here.

Model Brief

Before we start, we need to label all the pieces of this model. This is to establish a vocabulary that we can all use.

For this model, the key will be defining that signature spiral shape.

So, if you want to challenge yourself to start modelling, I would start by thinking about how you would solve these questions

  • How would you define the spiral?
    • Is it a curve? would you generate the ramp directly without a curve? Do you want to use a plugin for the shape (there are a few plugins that can help create helixes)
    • I created the helix from scratch but you don't have to.
  • Then how would you connect the helix to the roof?
    • The helix moves upwards and at some point, it has to merge with a flat circle to form the roof, how would you handle that transition?
  • How would you make the Diagrid?
    • How would you impart the "twist" into them?
    • Think about using the points of your helix to help with that

These are just some high-level conceptual problems to think about. Once you do solve them, the other smaller pieces like the handrail should fall into place.

Solution Brief

When you're ready, take a look at the solution guide below:

Spiral Observation Tower Solution Guide

This detailed guide walks you through every step of my script. It contains the workflow, the decisions and as well as my thoughts as I created the model.

You can also find the link to the script in the solution guide or here: