Are you going to park three cars in those three garage doors? 9ft doors are super cheap, ten foot doors jump in price. I've never heard of or seen a 9ft 6inch door, so that must mean they are being custom built. To me, that's just a waste of money.
There really is no room to open a door once you have three cars in there.
How wide is that big door on the other side? Ten foot is what I would consider the minimum, and that can be really tight if you want to get a trailer in there or an RV, or anything with big mirrors on the side of it. Mine is ten foot wide and my next one will be 12 foot wide.
Where will you store stuff? Will there be a work bench? Shelves should be two feet deep to hold anything at all. Same thing with a work bench. I wouldn't wan anything smaller. You have two long walls that would make great storage, but you only have a foot from the wall to the three doors. That really need to be four feet so you can have storage and park a car.
Do you have a porch over your walk through doors? They will rot on you if not protected. Every walk through door should have a some sort of roof over it to keep the rain from getting into the seals and rotting out the frame. This starts at the bottom and works its way up. It starts the day you install it and it just depends on how much weather you get as to how fast the rot proceeds.
I really, strongly suggest having a sink inside that you can wash things. Mine is close to the walk in door, and it's used all the time!!!!!
To be truly helpful, we need to know what you are going to use this building for, and what you plan on putting in there. In my opinion, seeing those three doors, I think that you are building it too small.
