This chicken pool is based on a project from Kansas. I followed most of the advices, with minor modifications for a climate that is certainly milder than the original one (and with much more sismic activity).
Here are images of the construction, from foundation to the finished pool. Material employed are pine, OBS panels, and screws (not a single nail, except for the roof cover). In general I'm quite satisfied. However, I think that the structure could be lighter. But the herds find it quite confortable (see eggs in last photo).

Colored eggs laid by mapuche herds, the first that inhabited my chicken pool.