I don't have details... It is a re-purposed poultry house frame. so it has proven engineering.
Not there, it doesn't have any engineering. Those are narrow width gable end wall panels, stick built by you, between and on either side of the three door openings. They need to be shear panels because of their narrow width. It's just prudent to detail them that way, and not just in earthquake country. It's just the cost of plywood, screws, glue and metal ties and straps.
And on another thread I see where you added length to the column portion of those trusses. Was that engineered, or jury rigged?
When you add length to a column, you are essentially adding length to a vertical beam. You are also adding load to that beam without increasing the section of the beam, or it's load carrying capabilities. In this case, the wind loads are the critical factor. Here again, I might have erred on the side of caution and added a member to the entire length of the modified column, to increase the section modulus. That's something you can still do BTW.
You see, if you don't at least do some rough calculations, you will never know the real capabilities of your structure. You don't know when or where it will fail.
I have to ask, what were the engineering specs for a chicken house? Are they the same load requirements for a building inhabited by people, like a workshop or garage?
And that engineering was for the chicken house as originally built, with the same exact cladding, roofing, length of columns, truss spacing, purlins and end wall construction etc.
You may be perfectly fine for many years, maybe for the rest of your life. You will just never know for sure.
Here's why. Buildings are designed and engineered to withstand a particular set of conditions, for your location. When this is done, you know how they will perform, and when they are in danger of damage.
End of day, I will say that I envy your clear span tall center height space and the initiative it took to build it.Were permits required?
Bill