My wife has gone nuts for chickens. I blame Pinterest. She wanted a coop for her birthday and some chickens... so here is how I built her the coop. The fenced in little yard part will be added later.

It works out that one sheet will make the front and back from one sheet. The sides are one sheet and the roof and floor are one sheet. For a total of three sheets or plywood.

Supplies:

Three sheets of plywood. The walls are 3/8" ($14 a sheet. I should have gone thicker but this worked). The roof and floor are 5/8" scrap from some other project (free).
4 - 2x4's at 6' long. These are the legs/vertical bits ($2 each)
4 - 2x4's at 8' long. These are the horizontal bits ($2.50 each)
Screws or nails for the siding, 1.5" drywall screws work well. (One box about $5)
Screws or nails for going through the 2x4's for floor, 2.5" Drywall screw work well. (One box about $3) Don't need as many long screws/nails
One gallon outdoor paint. ($10 messed up color from paint store)
Some kind of roofing. I used leftover 3-tabs from another project (Free)
2 hinges for big door (other project... free)

Tools:

Saw to cut wood. Hand Saw will work!
Screwdriver for screws, electric would be a big help, and/or hammer for nails
Wood Glue, Not needed but makes everything hold together so much better.

Step 1: Plans

The great thing about this plan is you can make it with hand tools... Saw, screwdriver and hammer. If you want power tools that's cool. All the important dimensions are allready done with the plywood. The other great thing is you don't have to be all that precise with dimensions. You have to measure within about 1/8" to 1/4" on the cuts you do have. Overall the sides of the plywood are the important parts and they come straight!

I made mine rather tall, because I am tall and wanted room under the coop for a swing (Chickens like to swing, who knew).

Step 2: Cuts

Cut plywood...

Sides are one cut at an angle (see pic) from one sheet
High side is 4' 6"
Low side is 3' 6"
Front and back are another sheet
Front is 4' x 3' 6"
Back is 4' x 4' 6"
Bottom is half of the last sheet. It's cut a little short for the roof.
4' x 3' 11" with corners cut out for the 2x4's (1.5" x 3.5")
Leftover plywood part is roof... that will be a little small for the roof... how did I do this?
Top is 4' x 4' x 1"

Step 3: Building - Back

Start with the back. Lay two 6' - 2x4's down and glue and screw the back to them.

Line the edges flush with the 2x4's and the plywood.

The top of the plywood needs to be 1" higher than the tops of the 2x4's to make the roof work

Add some horizontal supports at the top and bottom of the plywood.

Step 4: Building - Front

Cut two 6' 2x4 down to 5' 1"

Same as the back but the top of the boards line up with the top of the plywood.

Glue and screw and add in the horizontal supports.

Step 5: Building - Sides

Somehow you need to prop up the front and back. I used kids and my trailer, you can use... good luck.

Glue and screw the sides to the front and back parts. It's important to line up the edge of the plywood with the edge of the 2x4's not the plywood. See drawing.

Step 6: Side Door

Now you need a big door to clean stuff out when it needs cleaning.

I measured a big door and cut the side with the hinges first.

Then added the hinges (This is a trick I learned a long time ago.)

Then cut out the rest of the door out, voila the door is hung.

Step 7: Horizontal Floor Supports...

The floor of the coop needs some extra support.

Add a 2x4 horizontally across the bottom of each side, glue and screw.

Add a 2x4 across the middle, glue and screw through the back and front

Make sure things are square at this point so you don't have a wonky coop!

Cut some extra bits for 45 degree corners, glue and screw in the corners.

Glue and screw the floor in.

Step 8: Roof & Floor

Roof:
Need more support. Put a 2x4 across the top from side to side. *(This also depends on how thick your plywood is!)

Glue and screw. Then put the roof on. Glue and screw that as well.

It will be about 1/2" short this is all part of the plan and couldn't be helped. Center it from front to back.

Floor:
The floor ended up being thicker, I think that's good. Glue and screw it down.

Step 9: Finishing Up

I added some trim to the house and door. 1x2 glued and stapled on... and added a small chicken door that slides up and down.
Then everyone painted it with some leftover paint from the hardware store *(You can get deals on paint that's an off color. Chickens can't see color so it's all good.) We painted everything, top bottom, sides, underside. Because I didn't use anything pressure treated or particularly weather friendly, we slathered on the paint.

Did the roof with left over three tab shingles (free). You can roof it anyway you want.

I added some leg diagonals for added support because it's going to be a clubhouse for a few months till the chickens grow up a bit.

The egg boxes are next as well as the ramp, little lights, heater and outside fenced area. So stay tuned.