Henbhouse sizing

[WilderSkye]

We are in the process of converting an old 12 x 21 greenhouse into a chicken run, then adding a henhouse to the exterior that opens up into the run. We have 12 chicks coming this June, 6 of which are straight run, so expect around 3 roosters. Would a 12 x 4 henhouse be big enough for them? Or 12 x 8 better if we add more chickens at some point. Not that that was the goal, more hens, but I keep hearing about that chicken math thing. It doesn't need it too big as our winters are brutal and I read to not build too big as they need to cuddle up and generate heat.

We have researched up down and sideways and looked at prebuilt coops, but really, for the cost, we can build exactly what we want way cheaper, with better materials, such as hardiplank vs chip board walls. They will free range over our acre and we have future plans of doing that chicken run thing where you have seperate bays that you plant in for gardening, then let them in to till it up for you, and rotate to another bay for the next planting, etc and open up the old garden for them. We actually can grow about year around in spite of having an environment like Uzbekistan. I kept spinach beet greens, parsley, and other cold weather stuff alive all winter with lows in single digits.

Anyways, any thoughts welcome. I know this is an odd sizing but plan is to run it along the southwest facing end of the run.

 

[nuthatched]

Bigger is always better.

It doesn't need it too big as our winters are brutal and I read to not build too big as they need to cuddle up and generate heat.

That is a untrue myth, they'll cuddle just as well in a large coop. They won't heat up a coop with proper ventilation.
You want at least:
4 square feet per bird in the coop.
8 square feet per bird in the run.
1 linear foot per bird of roost bar.
1 nest box per 3 hens.
1 sq foot of ventilation per bird.
Roosts above the nest boxes, ventilation above the roosts.

 

[WilderSkye]

Bigger is always better.

That is a untrue myth, they'll cuddle just as well in a large coop. They won't heat up a coop with proper ventilation.
You want at least:
4 square feet per bird in the coop.
8 square feet per bird in the run.
1 linear foot per bird of roost bar.
1 nest box per 3 hens.
1 sq foot of ventilation per bird.
Roosts above the nest boxes, ventilation above the roosts.

12 x 8 will better then. I want to to run two roost bars on the same level. I do not want roost bars staggered. We will do an overhang with sofits, etc. for ventilation. I want it raised about 3' off the ground, and then add hardware wire to the bottom to give them a hidey spot under there when they are in the run.

One more question: is there any need to add insulation and put an inner wall? Our thoughts were to put insulation, then have the inner wall as slick as we can, painted with white pond liner paint to make it easier to clean an mitigate mites from nesting in the cracks. I suppose this is as good a plan as any. But is the insulation necessary? Our temps range from 0 to 90s in summer, super arid environment at 4600' elevation NM.

 

[DobieLover]

You do not need insulation. You need a huge amount of ventilation. And I would not restrict the size of the run to 8 sq ft per bird. 12-15 sq ft is more appropriate. 8 sq ft is just too small.

My birds have been in an uninsulated but painted coop for nearly 7 years and I've never had mites. I think people overestimate potential mite problems. They're generally carried in from wild birds. If you can limit wild birds interacting with your flock that will go a long way towards mitigating mites. And giving them more space and lots of dry material to dust bathe in as well.

What is your plan to mitigate the greenhouse from getting warmer than the outdoor temperatures in your climate? Heat will kill a chicken faster than the cold will. They need dense shade preferably on damp ground in order to survive extreme heat.

 

[nuthatched]

No insulation is necessary.

 

[WilderSkye]

Thank you for the input. We tend to over engineer things. The run is just for times when they can't free range, and while they are small. The garden chicken bay thing is to keep a rotating garden, let the chickens work for you in there, sort of a closed loop system. They will have an acre to play in during the day, I am outside all the time in our garden.

I think we have been trying to re-invent the wheel. Nearly 41yrs of marriage at peril over a hen house. Have spent weeks discussing this. What we have come to the conclusion is to order The Ultimate Chicken Coop plans and expand on that. Make it where we can scrape the poop from both sides.

And thank you for the insulation info. Do we even need sweeter heaters? We are getting 6 French Blue Copper Marans straight run, and 6 Alchemist blue females from Alchemist Farms. I already have a list of people with flocks who will take our surplus of roosters for their breeding program.

Anyways THANK YOU for the kind input.

 

[WilderSkye]

@DobieLover forgot to mention. The greenhouse is going to have a roof and the walls will be hardware cloth. It has been a major undertaking clearing it out. We will take the panels off when the winds stop. We have had some major gusts of 80 mph. Narrow window to work out there. It is horrible.

 

[StinkyAcres]

What are your lowest and highest temps?

 

[WilderSkye]

What are your lowest and highest temps?

Worst lows can be -9f. This winter only got down to 3f; high plains and arid with loads of wind.
Highs in 90s, with around 3 days of 103 at worst. I have been tracking it the last 9 years. Nine years ago low was -9 and high 90. Less rain now, too. Winters can be pleasant during day and plummet as soon as sun goes down.

 

[StinkyAcres]

Worst lows can be -9f. This winter only got down to 3f; high plains and arid with loads of wind.
Highs in 90s, with around 3 days of 103 at worst. I have been tracking it the last 9 years. Nine years ago low was -9 and high 90. Less rain now, too. Winters can be pleasant during day and plummet as soon as sun goes down.

Okay, no need for insulation or a heater in those temps. I do worry about the greenhouse overheating during the summer however. Even with open windows my greenhouse gets in the 90s during sunny winter days. Chickens have a much harder time cooling down than warming up. I'd replace at least one wall with hardware cloth.