The most logical starting point is to call a county and ask them if they know of yurts and if so, do they allow them to be permitted as residences or accessory buildings. You can't trust other people's experiences, because these things can change even as quickly as year to year. Hopefully for the better! But not always.
To do something under the guise of 'temporary' works for many, but leaves you open to the county being able to come in and either demand it be taken down, facing fines, or begin permitting it. The best bet is always going to be to know the counties stance on it. If they don't have a stance, then get the yurt and it's foundation drafted by a licensed, local architect and pay a professional to start routing it. That goes far. *edited to add* OR, wing it and if they come and make you take it down, well, easy enough. Heartbreaking in many cases though.
In Oregon/Washington, the biggest factor for codes with yurts is going to be
, so go with a company who sells insulation that meets the r-value factors. Other than that, I have found NO PART of yurts that pose an issue to the IBC building codes, or can not be made to meet them.
An excellent engineer in the area is Steve Kicinski. He is working with
on various things where yurts and pending IBC codes clash. His company is Ellisport Engineering. He would be an excellent person to speak with about codes in the area and I believe he is licensed in both of those states. But let's post yurt friendly/unfriendly areas as we know and we can begin a list of sorts for people. Where are you located again, Dan? County and state?