Scaling up a Woods' coop design dimensions plan

[saysfaa]

Upper Midwest, USA. Zone 5b give or take a zone or so due to lake effect.
Getting ready for 3 to 5 laying hens, starting with chicks, probably.
I'm in the process of designing a 12x20 or 16x24 Woods open-air style coop for 3 to 5 laying hens in a fenced-off section of a lawn and garden shed. I'm looking for feedback; like mistakes I'm making (I'm not mathy and don't have construction experience or much chicken experience) and improvement suggestions.

Our top priorities: either/both resale value of the property with the shed added or that the shed be easy to take down or move, and healthy and easy-to-care-for chickens, and an unobtrusive coop. I read our zoning ordinance and I think I can keep chickens without a variance but would rather not test my interpretation (residential can have chickens in limited numbers if the lot is big enough, Ag has no restrictions on chickens, our house is in a commercial zone and chickens aren’t addressed).

Researching led me to Woods’ coop as the best option for the chickens' health; I’m not sure how it would affect resale or how obviously coop it is compared to other shed styles. I got Prince Woods’ book through interlibrary loan a couple of years ago and copied it but I found it difficult to translate into a workable plan and it is inaccessible due to moving so I'm quite familiar with it but am not using it directly. JackE’s and HowardE’s threads are MUCH more helpful (thank you!!!!!), as well as several others.

Overall length and width in 1.6 ratio. So 10x16, 12.5x20, or 15x24 are my reasonable options..
Adjusting for standard size building materials gives me 10x16, 12x20, or 16x24

To see if I missed anything conceptual and because Woods’ says something about maximum of 20’ deep, I’m working on a 12x20 plan.
The back section length and width a square. So 12x12. Therefore, front section length and width is 8x12.

The height of the back wall of the 10x16 is 4’6”, plus half again is 7’ for a 12x20
The top of the upper monitor beam is 8’2”, so 12’ for a 12x20
That makes the roof slope about 5/12…

The height of the front wall of the 10x16 is 4’3”, so 6’4” or 6’5”
The top of the lower monitor beam is 5’6”, so 8’6”
That makes the roof slope about 3/12…

but 4/12 might be preferable because it is the minimum roof slope for snow country and the maximum slope that is reasonably comfortable to walk on. And seems like it would be easier for a beginner to build. And, maybe, it will look better to have the same slope on each roof?

Roof slope calculator gives 152” and 101” for the back and front roof length from the monitor beam to the outside of walls for 4/12 slope. That’s 12.66 feet for the back and 8.4 for the front. Plus overhang on all four sides, to be determined. And probably a bit of fudging to make rounder numbers.

The open front is about 12’ wide by 6’ high, most of the designs show one stud/post in the middle but 6’x6’ seems a bit too much span for the hardware cloth to be secure against even the smaller predators. I’m thinking put cross pieces in the openings so the hardware cloth will be fastened across 3’x3’ spans.

Are there guidelines for how much of the sides and/or monitor section should be window? Most of the info I've found has been on fudging the wall dimensions to get available windows in but I don't think that will be a concern with the larger sizes.

I'm working on the pros and cons of various construction types. Structural panels would be ideal, I think, but also not practical unless I get really, really lucky in sourcing them. I like post and beam or log and have the wood but can't move it except theoretically (theoretically, I can build a hoist or something but that is not realistic at this time.) Last time I did a detailed plan (for an 8x12 chickens-only coop) metal stud seemed less expensive initially but by the time I added the accessories, like tracks and cross pieces, it wasn't. But it was close enough to price it out again, once I have the design and all the dimensions. So, it will probably be standard wood stud and plywood construction.

It will work, won't it? If I get the mathy parts right or did I miss something about using only one side of the space or something like that.

 

[aart]

@Howard E @MiaS @Ted Brown

@jthornton has a clean copy of Woods book...might help.

Can't seem to tag JackE.

 

[jthornton]

Here is the Prince T. Woods Modern Fresh Air Poultry House book.

JT

 

[Ted Brown]

Upper Midwest, USA. Zone 5b give or take a zone or so due to lake effect.

Getting ready for 3 to 5 laying hens, starting with chicks, probably.

I'm in the process of designing a 12x20 or 16x24 Woods open-air style coop for 3 to 5 laying hens...

Why are you building for such a large coop for "3-5 hens"?

 

[aart]

I'm in the process of designing a 12x20 or 16x24 Woods open-air style coop for 3 to 5 laying hens in a fenced-off section of a lawn and garden shed.

I believe these proportions are off.
Width vs Depth is critical for 'Woods function'.
Check the plans.

 

[saysfaa]

Why are you building for such a large coop for "3-5 hens"?

Two reasons for the size. Most of the space will be for the lawn mower, snow blower, wheel barrow, shelves, ect. One side will be fenced off for the chickens, so if they will get about 5x20 (full depth of one side) to be full-time quarters. I figured 100 divided by 6 is about 16 square feet, since 4 for the coop and 10 for the run is the rule of thumb I usually see, that is just a little generous. It is also wide enough for me to move around in. Any smaller building wont be big enough to get the lawn equipment into the rest of the coop/shed with clearances.

 

[saysfaa]

I believe these proportions are off.
Width vs Depth is critical for 'Woods function'.
Check the plans.

Ok, if I build 12 feet wide, how deep should it be? I completely believe I did some math wrong; I can't see what. I took the 10x16 example from the book; a quarter again of the width is 12.5, a quarter again of the depth is 20. And compared it with the book's other small plan; the 6x10. Doubling depth and width gives 12x20. I've read threads here about people fudging the width from 6' to 8' or from 10' to 12' on smaller builds with good results, so it didnt seem like the possible 6" fudge on width would matter. If it does, I'll build a storage closet across the back, effectively shortening the depth. Is that the mistake or am I still missing something?

 

[Ted Brown]

@saysfaa You have your calculations correct, a 12 by 20 area gives the ratio that @Howard E discussed. But note that Woods himself never referenced that ratio nor did he go into any philosophical musing about why his dimensions worked. I cannot believe that 6" would make a difference

Building a closet across the back would change the depth by whatever and throw the ratio off. As @aart says the width vs depth matters according to Woods so one assumes this may not work.

When I originally read your post I also wondered about the increase in height. It seems to me that this may also change the air flow characteristics of the KD design.

I spent a bit of time this morning scanning the Woods book and the various designs therein. One could argue that the open front is the critical bit and exact dimensions are not; certainly the dimensions across the multiple designs do not conform to the "golden ratio" so I question the analogy.

I was troubled by your response to my question given that you want a multi function building and machinery storage is part of that. That means fumes and likely gas or diesel and oil and... I suggest that these are not compatible with livestock. I am not an expert but my grandfather was a farmer all his life - machinery was either stored outside or in separate sheds apart from the live stock.

To summarize:

1. I would build a coop, possibly with areas devoted to storage and not mix usages.
2. I would stick with the dimensions given for various designs or come up with something else on your own (many people go this route, I would not). Specific designs tout different advantages, if one changes the basics the advantages may not apply.
3. If you need storage for machinery build a garage.

A final note. I am not an expert, these are opinions and random thoughts.

 

[saysfaa]

Good point about the fumes. We have a garage already; we just want to put the cars in it. The existing garage has enough room for the cars and a snow blower in the winter. So it should have room for a lawn mower in the summer. Probably for the next most fume-y things too, like gas cans, if not all fume-y things. We recently moved from a house with a much smaller yard and a different climate so are in transition.

The height changes were an attempt to keep the proportions workable because I think changing the width and depth without changing the height would change to airflow as much as changing the height without changing the depth and width. Some things don't scale proportionally (in general, not necessarily coops) but until I can find more info I assume this will.
The closet across the back was an attempt to fix the width/depth issue aart saw, or what I guessed was the issue. I'm thinking whatever depth of closet makes the airflow right; I can tack some plastic up to find that depth by trial and error if it becomes necessary. It would open to the exterior at least behind the roosts, even if it were only deep enough for hoes and pruning shears it would be useful. I don't think it will be necessary. For one thing, it should be easier to scale up than it was to scale down because the margins of error are bigger.
Thank you for taking the time to look into it and for the thoughts and opinions.

 

[Ted Brown]

An observation, no insult implied. You are making lots of assumptions without factual basis.

Again, if you find a design that appeals to you and has the benefits you are looking for then build that without modifications.