I made this little chicken barn a few years ago to house 3-5 laying hens in my back yard. I'm in town and had to design a "pretty" one to keep people from having a chicken coup (ha ha). This one was inspired by some Kansas barns I've seen. I spent about $40 when fully completed. Chicken wire, some 2x4s and damaged siding were the costs. Damaged siding is half price at my local lumber store. Other things used were scrap wood from old bathroom cabinets, leftover hardware, paint, and wood from house projects, and lot of scraps and hardware from a condemned house down the street (I got permission to take things before they bulldozed it.) Shingles were given by my neighbor leftover from roofing his garage.

There are some basic rules for designing and running a good healthy chicken shack:
1. Adequate floor space per bird.
2. Dry with good ventilation.
3. Temperature control.
4. Predator protection.
5. Keep it clean + fresh water/food = happy & healthy birds.

Many towns actually allow up to 5 chickens but no roosters. Check local rules on this if you plan to build. If you do get chickens in town, be courteous to the non-chicken majority so the rest of the city chicken people don't get punished through politics and zoning.

I submitted pictures of this coop to someone who was working on a coops book a while ago and they included a picture of it in "Chicken Coops, 45 Building Plans for Housing Your Flock." By Judy Pangman

Sources for my chicken knowledge:
"Building Chicken Coops" Gail Damerow
The City Chicken, http://www.thecitychicken.com/
Backyard Chickens Forum, http://www.backyardchickens.com/f/
FeatherSite - The Poultry Page, http://www.feathersite.com/Poultry/BRKPoultryPage.html

I recently posted another coop, a chicken outhouse with a beer can roof at diylife.com

Step 1: Floor Space, Framing, and Nest Boxes

My floor space includes the exterior run. I knew I wanted 3 heavy egg layers, so from the charts I used 10 square feet per bird rule. There are different suggestions in different books/guides; this link has a pretty good chart: Virginia Tech Small Scale Poultry Housing PDF.

I built this 18" off the ground to create a shady part of the pen underneath the coop.
The floor is 2x4s framed like a little porch 3 feet by 4 feet sitting on 4x4s attached with many 3" screws.
The walls are just under 4' tall and I used 3" screws to put together the 2x4s. 4' walls are a good dimension because siding and plywood come in 4'x8' sheets.

I framed in nest boxes here. I think a rule is one box per 3-5 laying birds. They like dark, comfy places to lay. Making the boxes the size of a 12" dust pan works great when cleaning the coop. Lots/all books suggest elevated boxes, but these floor boxes have worked great for three years now.

Avoid treated lumber inside the coop or where they perch; the toxic stuff can affect the birds (ie. sickness/death)

Step 2: Roof

I don't have many step by step pics for this so you'll have to use your skills to fill in the gaps.

I cut 2x4s with angles to make three sets of rafters and attached them with three inch screws. I screwed down some old cabinet wood across the rafters to make the roof, leaving a little 4" hole near the center peak for a cupola. Then I shingled the roof leaving the center peak hole open.
The cupola is made like a little bird house that sits over the vent hole. Use a hole saw to make holes in it's sides and staple window screen on the inside to keep out the critters. Attach it with 3" screws.

This helps meet rule #2.
Dry with good ventilation.

Step 3: Walls

Cut the siding to fit the framing and attach with nails. Use a jigsaw to cut out doors and other openings; save the cutouts for building the doors.
Keep the following in mind while designing walls:

Make openings for windows; this is important for summer heat control.
Build walls tight to keep out wind and drafts; this is important for winter cold control.

This is a standard chicken coop rule: Have good ventilation but no drafts.

Step 4: Doors

A main door to access the coop and a small chicken door are the only doors really needed.
But I added cabinet doors, a nest box door, chicken door and a main door on this thing.
Hinges were from old bath and kitchen cabinets.

The main door is made with old porch flooring. Boards were attached diagonally to the siding cutout with nails; then I used the jigsaw to clean it up around the outside. This made a more old fashioned looking door. The nails will stick out the back side, bend them over or cut them and grind the stubs smooth.

The other doors were made directly from the siding material and some trim wood. I just attached hinges and handles with some trim around the edges. The trim is important to close the gap from where the saw cut the siding. I added some plastic near the top to shed rain over the cabinet doors.

Step 5: Finishing Touches

Add the roost perch for night-night time.
Make a perch out of a 2x4 with the edges rounded a bit. Under the perch make a place for the poop to gather. This roost area is usually the only place that gets poop inside my coop and makes cleaning easy. (Don't use treated wood!)

When I finished the coop, it ended up being very heavy; so I attached some boards to the bottom and used a hand truck to wheel it (with help) to its home location.

The run/pen can be made easily with 2x2s and 2x4s as seen in the pic below. I enclosed the top of the run to keep the hawks out. I later added a matching run on the opposite side when I added some more hens.

Step 6: Extra Notes

UPDATES: I've changed the coop a little over the years to allow for more birds. I've removed the storage area and added a roost in its place.

Also, I've removed the small pen and made a large run for the birdies.