This very small Coop is modeled after my 10yo larger coop and is somewhat of an experiment although it is a very real usable Chicken coop. I intend to measure it's efficiency and performance thru the winter (NOTE: I did, ... very successful)
It's 4x4, enough for 2 or 3 Chickens but CAN be made in ANY larger size for dozens of Chickens. My existing much larger coop/aviary is plenty large enough for me to walk inside, and the Chickens can fly. Short sleeve shirt is all you need and be warm on a sunny cold winter day.
.. This is NOT the way I would usually build one. This one is built in 3 detachable pieces so I can bring it to my "The Art of Keeping Chicken Classes" in my van. One built to not be portable would have much less material and would look less complicated and it can easily be made to look "cute".
The idea is to gain as much energy from the sun as possible while at the same time make the coop very efficient to maintain with Chickens in it. Even with NO sun the aviary portion is usually 15 degrees warmer (free) than outside while the coop is always above freezing. The angles and proportions are important. The ventilation, fans, sizes, timers, lights, etc are also very important. Many other details are also very important to it's success. It's mouse-proof also. Snow usually slides off of the solar surface, if not, a gentle tap usually causes the snow to slide off.
. . The solar surface area ratio to the cubic feet is much smaller than my other coops so it will likely cost about the same or more in electricity to heat as my MUCH larger coop (maybe $5? per year for the small one?). Other aspects of the coop are the same as my larger coop (Easy to clean, etc).
NOTE - It actually only cost 24 cents to keep this mini coop above freezing for the entire winter.... my large 20 Chicken walk-in coop only costs $5 to stay above freezing.
Most of my Chicken keeping methods and techniques are not apparent from the photos.
. . In winter the entire outside area is covered with inexpensive 8mm clear plastic (shown in the photos) over the 1/2" wire cloth. That retains the solar gain and protects the Chickens from drafts of any kind. In summer, the solar surface is covered with foil backed foam panels to give the chickens the coolest place they can possibly be on hot summer days.
I
t is almost December ... about 25 degrees outside, but quite warm in the aviary (100 in sun). That excess aviary heat gets drawn into the Coop warming it for the night. In summer the solar surface is covered with a cheap reflective panel making it the coolest place the Chickens can be.
“Solar Powered Chickens” coop, coop-design, solar, aviary, chickens
It’s a smashing success. Ace just built this Chickens solarium/aviary for Bert and the hens. It’s connected to the coop inside the pole barn via a skyway with a gravity airlock. The coop always remains above freezing day/night. The Solarium gets too hot during the day, heating the coop for free in the process. At night the solarium cools to the ambient temperature, but the insulated coop stays warm. In summer there are numerous vents and windows and it keeps the coop cooler by keeping the hot sun off the shed wall and dissipating the heat. 
The floor of the solarium is covered with 5” of dry sand so is like a huge litter box for very easy cleaning with a long handled rake/scoop. The Chickens are free to roam the yard anytime except on days when the temp does not get above 20 deg the Chickens will be confined to the draft free warm solarium where they can still fly just a bit and take sun-baths. The Chicken door is a sliding glass door.
Today it’s 30 deg but the aviary air temp is 82 in the shade, 122 in the sun. It will double as a “greenhouse” for plants in the Spring. In Minnesota it can get down to minus 40 (C and F deg).
Houses should be build like this.
UPDATE 10/2010 - Solar Aviary addition
The entire aviary-coop is mouse proof. Even on a overcast day the temp is 10-15 degrees warmer, with sun 60-90 degrees inside. When the sun comes up a thermostat/fan blows hot air from the aviary into the insulated coop so the coop stays warm the next night without any additional head source. It remains above freezing for almost no expense ($5 per year for elec heat at temps lower than 20 below, otherwise free)
With twice the floor space the Chickens are very content to stay in the aviary when the weather it too nasty for them outside. The sand floor is very quick and easy to clean and keeps it very sanitary for the Chickens, and it also acts a bit like a heat sync to store heat for evening.
The sand floor has roofing "Ice-Shield" for a waterproof basin for the sand. The Chickens love to take dirt-baths and lounge around in the sun.
For INFO and specs on the insulated coop inside the pole barn, see :
http://bertthemensachicken.multiply.com/journal/item/190/What_happens_in_the_Coop_stays_in_the_CoopView the Chickens in the back yard anytime via Live Chicken Cam... you control the camera
http://bertthemensachicken.multiply.com/journal/item/217/CONTROL_Berts_CHICKEN_CAM_search_for_Chickens.
