How does one design around the expected shrinkage with drying green or semi green timbers in a structure that is about 275 feet long? The structure in question is a set of opposing stalls 12x12' with a 12' isle between with hay loft above that serves secondarily as a buttress system on a large 100x275' indoor arena. The arena cover is engineered metal truss with fabric cover. There is a central bump-out aspect that will be about 35' wide. That breaks things up a little...but Yes, a huge project! Verticals are 10x10" with fully housed 8x8" and 8x10"members and 4x6" braces. Roof pitch is 8/12.

So, if there are 2 "stall sides" with 10 sets of the 12x12 stalls each making 120', each side will have 12 bents, and if each of those bents' 10x10" vert beams shrinks 1/4-1/2" then the structure will either bust pegs (I'm guessing) or it will contract by several inches, which concerns me as the roof of the timberframe stalls/hayloft is to be contiguous solar panels. Just to be sure, I know the length of each member is stable...just not the 10" sides.

I considered designing the central bump-out as a separate structure, but that gets complicated and the structure looses some stability as a whole. Buying standing dead timber or dried timber comes to mind, but that is cost prohibitive. Some woods shrink a little less than others such as eastern white pine, so that has been another possible solution. I could also potentially purchase the entirety of 10x10 beams, or all the material, now, over dimensioned at 10.5x10.5", for example, and let them dry in open air (covered) with ends sealed for 2 years before planing to dimension and doing layout and cutting my mortises, etc.

I have done all the reading I can on this, but I am hoping for some experiential anecdotes or steering me towards resources that I could further read and digest to answer this question and allow me to move forward with the design.

Thanks!