greenhouse Avoiding Code on a Greenhouse Build

Looked into code when I built my fences and high tunnel.  Followed the rules that let me escape needing permits and following code.  That and having the University of Kentucky plans to show them didn't hurt things.  Now thinking about building what they call a Deep Winter Greenhouse.  Essentially, the North wall is thick with insulation and the South wall is very steep to let the winter sun pass at a right angle.

If the structure has poles in the ground, I need a permit, inspections, and so on.  If it is sitting on a platform, no permits because it is considered a temporary agricultural structure the same as a high tunnel.  Behind my barn is a partly burred concrete surface that used to be the foundation and base for a grain silo.  Thinking it would be perfect.

Thing is, kind of wondering why more structures are not built that way?  Entire homes, single and double wides, are built as platforms.  Is it fear of tornado?  My high tunnel is three years old.  The rolled plastic needs replaced from storm damage, but it is PVC and even that has held up to our bad weather.  Maybe a fix here and there.  But really thinking platform builds make more sense money wise.