Questions about straw clay and timber frame

Hi all. I am researching how I want to build my house once I find the right Piece of land in the UP of MI. Up front I have no experience so if some of the questions seem rudimentary, well, that's why.

My goal is to build a house that could last for 100s of years as cheaply and simply or quickly as is reasonable.
So I want to use my own timber to create a timber frame  house and I'm thinking I'll use straw clay as the infill.

My questions are:

1. Is round wood (less processing) the easiest/ least time consuming timber frame method when using your own timber or is it easier to square it so the rest of the process goes smoother?

2. Most of the pictures I see of straw clay building have the timber frame exposed to the outside, is there a way to avoid this? I like how I've seen some hempcrete construction pics showing the hempcrete completely encapsulating the wood but that uses a lime binder which is expensive. Would I be able to do that with straw clay or would that be more prone to rot?

3. I've heard you can build with green timbers, but how green. Can I start using them as soon as I chop them down and how would green timber effect straw clay?

Have you seen this book?  It might be helpful:

Mudgirls Manifesto: Handbuilt Homes, Handcrafted Lives by The Mudgirls

https://permies.com/wiki/87449/Mudgirls-Manifesto-Handbuilt-Homes-Handcrafted

I built a straw-clay house that mostly had dimensional lumber trusses (hidden in the walls) with some exposed timber framing.

1. I think rectangular timbers would be easiest to build - especially since you want to conceal them. Also you can take advantage of smaller lumber with concealed ladder trusses. You attach the temporary forms to the trusses when packing the straw-clay.

2. Concealed framing is no problem - in some ways it is easier. You do need to prepare the joints more where the plaster covers the timber/straw-clay joint, but that is pretty simple. The wood will be fine as long as there is a good roof, foundation, etc.

3. The timbers we used were fresh felled trees (forests were closed due to fire hazard until we absolutely needed the timbers). There was more twisting and checking of the wood, but it turned out fine. The species of wood affects how timbers behave when green, but it generally works.

The first thing I would suggest is building a strawbale house rather than straw-clay. Your location is cold, and strawclay isn't the best insulator. Strawbales, especially mixed with light straw clay interior walls make beautiful long lasting houses for very cheap. Strawbales are also much easier to build with and can be plastered just as well as light straw walls.

If you are set on straw clay, you can hide timbers in the walls even if they are round. The green-ness of the wood shouldn't matter, but it will shrink a bit as it dries, it won't have an ill effect on the straw material though.

I am not too sure what straw-clay is.

But I like a strawbale house that has a plaster of cob on the outside. I selfishly hope this is what straw-clay means.

Also alot of these house that last 100's of year needs to be repaired every couple decade, maybe even more often esp the roof.

EDIT:
Check out these guys and let me know what you think of it and how it compares to the idea that you had in your mind.
https://permies.com/t/60866/balecob-home-earthbag-foundation-building

Hey! thanks bengi for linking my thread. For quick info, that is a house made from strawbales with a good thick layer of cob on the inside of the exterior walls. It also has a few light straw clay walls too. It is load bearing but with 3 posts supporting the roof in the center.

Thanks guys for the replies. I like the ladder truss idea.
@ S Bengi & Daniel, I love the look of straw bale, both straw bale and straw clay have their pros and cons. Straw clay is straw coted with wet clay, usually very lightly so that the straw just looks dirty and damp but is still fluffy. The benefit of this over straw bale is that the clay acts as a preservative and makes the walls more forgiving to moisture and resistant to rot. There are 800 year old straw clay houses in Germany. It however can not bear loads like straw bale. I'm willing to settle for less R value for the added rot resistance, I also hear that straw clay has more thermal mass which might make up for the lower R value. still with 12" thick walls I think it will be plenty. As for easiness of building with, Ive heard both bale and straw clay take the claim as easiest. I suspect it depends on the house being built as well as what the builder personally enjoy working with. But for example I understand that straw clay is easier to form around windows and doors because their is no cutting and retying the bales into shape, you just stuff it, so a house with lot of windows and doors might be faster/ easier with straw clay but a more simple construction  might be easier with bales where you can build them like blocks. Ive' heard of people using both methods where they use straw clay on the south and east walls where there are a lot of windows and bales on the north and west walls.

Here are some google pics for Bengi


the forms are temporary to shape it