Platform ideas?

[Corinarose]

I used the

pacific yurts

design and the piers sit on the ground--not below frost.
I have had the yurt 3 years now and no heaving.
I think if I did it over again I would put in piers/sonotubes below frost line(4' where I am)
and the 2x10's 2' apart not 4' apart~ especially if you are planning on year round living.
But then I would also consider earthen floors rather than wooden ones ~ although I do like my wide pine floors.
Corina