Good space, will be a bit tight for 26 birds though. Having more roost space will be good too, if possible. And hardware cloth over any opening larger than 1/2" diameter!
Is there a dig proof foundation? Consider adding another layer of wall boards, depending on your climate, and whether or not you have predator protection outside. Rats and raccoons will work to chew through those wall boards.
It's a good space though, good work so far.
Will you be getting all those birds at once, or starting with a smaller group, to be added to each year?
And having your approximate location on your profile helps a lot here.
Most of us underestimated the need for predator protection necessary when we started. We sure did! Build Ft. Knox, and have a better experience from that first year.
Mary