Looking at the dimensions, I think the original probably has 3 feet by 3 feet of "house" part (not counting nestboxes), which makes 9 square feet. If you need 4 square feet per large hen or 2 square feet per bantam, that would be enough for about 2 large hens, or 4 bantams.
I went and looked at the website-- it says "Sized to comfortably house four hens – up to six if they are allowed to range freely during the day."
https://www.williams-sonoma.com/products/cedar-chicken-coop-with-planter/
So either they're figuring for bantams (2 square feet each), or they think chickens need half as much space as the amounts commonly recommended here.
I do agree with the manufacturer that all-day free range would slightly increase how many could fit, so I think 6 bantams could work in that case.
I decided a long time ago that coop manufacturers must be figuring for bantams when they list capacity
If you doubled each dimension when building yours, yours has four times as much floor space, which is a big improvement! And I like your great big run
I went and looked at the website-- it says "Sized to comfortably house four hens – up to six if they are allowed to range freely during the day."
https://www.williams-sonoma.com/products/cedar-chicken-coop-with-planter/
So either they're figuring for bantams (2 square feet each), or they think chickens need half as much space as the amounts commonly recommended here.
I do agree with the manufacturer that all-day free range would slightly increase how many could fit, so I think 6 bantams could work in that case.
I decided a long time ago that coop manufacturers must be figuring for bantams when they list capacity

If you doubled each dimension when building yours, yours has four times as much floor space, which is a big improvement! And I like your great big run
