What recommendations for barn building would you provide?

I need to build a barn (mainly) for my goats, (possibly) also including a compartment for my rabbits, chickens, (ducks) and some little extra space. But the priority lays with the goats, the others already have, will soon have their respective shelters.
Matter is, I’d like to keep as many together as possible because of the following:
– Must economise land space dedicated to the shelter(s);
– Winters here may peak below -22 celsius, so more animal groups providing warmth to each other is an option I am fond of.

Since the land available is not in a building area, the barn can be only entirely out of wood, or (but this needs a bit of clarification) only with three stone/concrete walls, one wooden. (curious, ey..)
By the way, for those who may not know, I’m not in the U.S.

Since the objective of the farm is to employ as vast a variety of materials as possible, mainly by re-purposing the ones already present, or easily available. This, of course, the lowest portion of budget as possible. This has been the policy up to now and has been more than satisfyingly efficient. So.. I will anticipate that I won’t consider greatly options that require great expenses, expect for proper insulation, of course.
(But, just for that I thought of a combo of styrofoam and tetrapacks.)
What say?