Thanks for the replies so far.
I understand that having some degree of flexibility is always a good idea. However, I would assume that if "approved" architectural drawings called for, say, '12 tiers at a height of 288cm', then that would have to be rigidly followed. -No room for 'mistake', and thus making the building a bit taller or shorter. But, I suppose this all depends on where you live, what the laws say or don't say, what your own personal preferences are, etc..
The good news here is that all car tires are quite flexible. So, despite their lack of consistency whilst empty, they probably are able to adapt to most plans/desired-heights when packed (-assuming they're not all thicker truck tires, bus tires, etc.). From my understanding, many Earthship builders don't just grab every tire offered to them. There is a considerable bit of care in the selection process. I imagine I'll be just as selective.
(For those curious, I am designing thoroughly insulated, freestanding Earthship-like homes (i.e., without berms), and with many of the walls 2-tires thick for the additional thermal-mass as well as stability. For several reasons, designs along these lines require a considerable degree of tire-size consistency. I hope to get around to sharing these ideas/concepts in a future post.)
-Joe L.
