Hi Ric,
A probing question, and the short answer is no.
I went to the local council office first to enquire whether I would need a planning permit, and since I live on a few acres with lots of trees, the neighbours were not going to be visually affected by the construction, so the simple answer was that no Planning Permit was needed. (Some years previously, I did have to obtain a Planning Permit for a tower that I erected here.) I think that they also asked about project cost, and at the time I thought that it would be well under the figure that they stated.
However, I then asked about a building permit. This function was outsourced from the Council so I rang around a number of building surveyors. My enquiries were met with widely-varying answers. Finally, I found one who was actively looking to help me proceed without the need for a permit. I don't know why the others did not follow the same rules, or even themselves have a consistent approach.
The criteria that the project had to meet (to not need a building permit) were:
- Does not need a Planning Permit
- Walls not greater than 3 m high (this doesn't include the dome)
- Is not built of masonry
- Is not more than 10 square metres in plan
- Can be called a "shed" (which of course it is)
Apart from the extra cost of a permit ($450 min), I am sure glad that I did not have to debate the plan for this circular construction.
Chris