d(>_<)b :
We are looking to get about 3 hens and then maybe a rooster one day. The floor is 4' X 4' and 26" from floor to ridge. It will be elevated 15" off the ground. The nest boxes are 10" wide by 8" tall by 10" deep. The run area is approximately 10' with access under the platform for shade. Is this big enough for 3 hens and a rooster? Are the nest boxes big enough?
The total area is IMO good for a 3-4 chicken tractor. However I would join everyone else so far in urging you to seriously consider a box-shaped design instead of A frame. It is not really much of any harder to construct, requires only minimally more materials, and gives significantly more useable room for the chickens. At the very least, consider making the HOUSE part box-style -- being a rather broad triangle, as per your plans, they will only have about 2-3 x4' of actual usable room, making it somewhat of a waste of construction materials for the rest of the supposed area
Remember that, if necessary for weight purposes, you could make the house and pen separate (latch-together) parts.
I couldn't tell from the plans, but hopefully the house part has good ventilation (like, at
least 1 sq ft on both front and back, even when pop door is shut)?
Also, where are you located? Tractors are real hard to comfortably and effectively winter chickens over in Northern areas, for a variety of reasons including
but not limited to the great difficulty of providing sufficient winter ventilation while at the same time not having a frosty blast of wind aimed at the chickens. So if you should happen to live somewhere up North, you might want to consider how/where you will winter your chickens.
Good luck and have fun,
Pat