I think the article is very well done. There are detailed instructions, detailed specifications, and lots and lots of well explained photos. That's why I rate this as a full 5-star article.
The concept of mixing the rabbit and chickens I'm not so sure about. For space, as long as the lower area is ALWAYS open and available my math says you'd have 32 square feet, with is acceptable for a coop to hold 8 chickens. As you say, the run space is not included in this.
-Copied from the first page:
"(2022-3-4) Update/Clarification:
Since many people have pointed-out a size 'problem' with this coop, it is worth strongly emphasizing that this coop is designed to be placed within a giant, 9x9m (~30x30ft), 81m² (~900ft²)(!), predator-proof pen, -far more 'round-the-clock space per bird/rabbit than countless setups I've seen. Under ideal conditions, the bottom, boutique "pen" of this house should remain open at all times. Overall, if you believe only 3 chickens, say, should sleep inside this particular house at any one time, than that's your prerogative. Regardless, this was the first time I had attempted something like this, and of course I would change many, many things in future builds. ~Thanks for looking!"
This is *just* the coop. -Not the coop + pen. The pen that this coop goes into should be large (≥9x9m) and, of course, 100% predator-proof. That was up to the buyer to construct. -And she did.
The detail is great, and the article is well written, a bit more consideration into space requirements before construction would have been beneficial, though.
"(2022-3-4) Update/Clarification:
Since many people have pointed-out a size 'problem' with this coop, it is worth strongly emphasizing that this coop is designed to be placed within a giant, 9x9m (~30x30ft), 81m² (~900ft²)(!), predator-proof pen, -far more 'round-the-clock space per bird/rabbit than countless setups I've seen. Under ideal conditions, the bottom, boutique "pen" of this house should remain open at all times. Overall, if you believe only 3 chickens, say, should sleep inside this particular house at any one time, than that's your prerogative. Regardless, this was the first time I had attempted something like this, and of course I would change many, many things in future builds. ~Thanks for looking!"