I was a bit surprised when you didn't put a wooden header or an arch above the window but rather just a big gob of cob. I guess because there is not a lot of weight above it and if you don't get much (or any) snow load it really doesn't matter. 5 years sure is proof though!
Nice video Yannick! Thank you for sharing.
EDIT - BTW, your chickens sure look like they appreciate your hard work!