Chicken Coop

In the summer of 2020 I designed and helped build a chicken coop in Upstate New York to house 6 hens. I had about two weeks to do the design in AutoCAD and get a material list put together so I got to work researching what is considered a “good” coop design. I found the book “Open-Air Poultry Houses For All Climates” (found here) which was incredibly helpful in understanding the most critical design features for a coop. I initially thought that good insulation was important as the weather Upstate regularly drops below 20 degrees Fahrenheit for a quarter of the year; however this was not true as good insulation prevents the circulation of fresh air. The hens just had to be kept dry to remain comfortable, even in harsh cold weather.

Design

I reviewed several coop designs online and noted things that I liked and disliked. Many of the coop designs seemed to be cobbled together and did not use best practice for simple things such as the roof structure, so I found some shed design and Larry Haun construction videos, which I highly recommend even if you have no interest in construction. He is basically a Bob Ross/Norm Abram of home building, link to a video here. Based on the design concepts I noted, I drafted the plans and made several revisions for about a week.

Features Worth Mentioning

Anything touching the ground is treated to prevent rot
Standard structural fastener is a 10-penny driven pneumatically for shear strength and speed of installation
(2) 2×6 top plates per 4×4 post, that sit directly on top of posts to directly load the posts and not fasteners
No ridge beam used for ease of installation
Rafters use birdsmouth joints to mate with top plates
Rafters have overhang trim on each side and roof has drip edge to prevent the structure from getting wet
Plywood sits flush with collar tie, posts, and floor framing for structural strength
No soffit installed to allow fresh airflow (wire mesh used to prevent intruders)
Roof uses architectural shingles for decoration
1×6 pine board and batten siding for decoration
Every window and door is fully framed in 2×4 for durability
No additional foundation posts needed for flooring to provide hens additional space
Nesting boxes and windows can easily be locked and accessed from outside the coop
Coop house door has floor plywood visible to make coop cleaning easy

Construction

You might notice that the drawings are not very detailed. I didn’t have the time to build engineering prints and I was acting as the contractor so I just built the simple CAD models, cut the model layers up to build what are essentially instruction sheets, and winged it on-site. There were several times I had to revisit the CAD files and grab some dimensions or do a quick design change but overall the construction went very smoothly with no moments of regret or realization that the project is doomed.

It took myself and one other person 7 days of 8-10 work hours each for start to finish construction, except for the wire mesh. Painting was done with 4 people and took a day. The worst part of the project was the roof as we did it in June and it was sunny so the shingles became hot quickly.

What I Would Do Differently

Upon completion there were a few things I noted that I would do differently for the design and construction. These are the three major changes I would have made.

First, I would design and plan more. It would have made construction much quicker to have more detailed drawings that were carefully reviewed. The biggest time sink was building the nesting boxes and the large door as the CAD design was poor. These were not complicated to construct but not having confirmed dimensions available created the slow down. I did not have much time to do design work but I could have squeezed more in if I had known how much construction relies on every design detail.

Second, I would have more carefully determined the material list. Due to the lack of detailed design I was unable to carefully put together an accurate material list. There was too much of some materials and not enough of others. This added to the total material cost and added time required to drive to the store.

Third, I would have set the posts deeper as I was unaware of the frost line being 36″ for the location of construction. The posts were set 12″ and there is a risk of the structure becoming warped when the ground freezes. As of writing, the coop has survived one winter where it sustained Upstate New York cold weather and several feet of snow with no signs of structural issues such as warping and binding.