For a green house I'm considering laminate post and beam construction, as described here:
Laminating small timber frame
For piers I thought I might set
16-Gauge Structural Metal Track into cement.
They are rather strong, and two lengths set 4.5" apart, the openings facing one another could make for a cheap socket to set my laminated beams into.
Through bolted in place, with a spacer to keep the ends off of the concrete, I could build up from there.
I originally thought to use bed rails in a similar fashion as they are even stronger, but they are harder to cut or drill, and not as perfectly suited to 2 x 4 construction.
Setting the bottom of the posts in gravel/rocks, and or using cedar for the bottom of the post are possibilities, but right now I'm leaning towards a concrete/rubble pier with diagonally driven rebar or bed rails to resist frost heave.
My site is really hard to dig in, filled with rubble from the house burned down, so avoiding belled piers is good.
Getting enough stone is a balance between time, money and effort.
Buying a bag of cement is cheap, easy and I can add on hand rubble to the mix for even greater economy.
I wouldn't bother with any piers at all except I REALLY don't want my structure to blow down.
My fence on that site already did, it hurt my pride
Buildings have an advantage against wind, but I also plan on keeping more important contents inside.
Plus, I like to get smarter from my mistakes...
Anyhow, what do ya'll think?
(Edited for working links)