Don't know why this image doesn't show. Here's a link.
The semicircular walls of the night roost and laying area are made of cob - sand, straw, water and clay from under the concrete driveway that we removed. Many friends helped stamp the mix together and slap it on. It has a raised floor of hardware cloth with removable slats underneath for cleaning. It has ventilation holes in the three part wooden front and in the cob wall. Also several window tiles and a beautiful nesting area away from the light, with an egg stealing door to the outside. The roosts are branches from a volunteer apple tree that we removed.
The enclosure is covered with a corrugated plastic roof and designed to be raccoon proof and hopefully deter rats, with daytime roosts for my flighty Marans. The compost pile is at the other end for easy disposal of chicken waste, and it will be occasionally open for play. There is also outside access at the end for adding garden material. Above the cob house is an area where I will take advantage of the extra warmth from the chickens at night to propagate seedlings.
The whole thing was made without concrete - only pre-made hollow concrete bricks that the found wood 4"x4" corner posts stand in. All the wood is recycled. It measures approximately 12' x 5' x 6' high.

Link to BYC