Try side by side - if that doesn't go over then try stacked. Your pullets will let you know what they prefer pretty quick. My one layer prefers the box all the way at the end WHEN she lays - I have 3 boxes and they are side by side up 18" off the ground.
I also thing side by side. That way there won't be roosting in front of the top one, which is over the opening for the bottom one. I recall my mom saying the chickens she had as a kid squabbled over the perching spot for the top box because it was recessed back a bit, like you have yours. I don't know if the lip will hold a big girl to land on and jump off from, from the picture, if you were to have the fronts at the same depth. Having them closer together and side by side isn't a problem, if space is the concern.
Good point about elevation in respect to the roosts.
The threshholds on my nests are 19 inches and my roosts are 24 inches AFF.
If the elevation is not a problem, I would go with the stacked option. More open floor space. Some heavy or older birds (Silkie too) prefer staying low.
Watch out that if they can reach the pink boards on the ceiling, they may peck them to bits.
Quote:
yeah those are really to protect the birds from hurting themselves on the nails that stick through the roof from when i nailed the shingles on. i just stuck the insulation sheets right on them. i was thinking that might be an issue with pecking. if that happens, i'll just pull them off and bend the nails sideways with a hammer, but there's so many, this way was easier.
thanks everybody for all the advice. i think i'll just stick with side-by-side for now. floor space is not (yet) at a premium... i only have two birds at present; the rest will come as chicks in january and won't be introduced to this new coop for a while.