DIY Red Barn Chicken Coop Plans: 8x12 Walk-In, Covered Run, 20 Hens

DIY red barn chicken coop plans for an 8x12 walk-in coop with a 16x8 covered run under a monitor roof with clerestory windows for 15-20 hens. Step-by-step PDF.

- Product: Thornbury monitor-roof walk-in chicken coop with clerestory windows and covered run, building plans
- Format: Digital PDF download
- Pages: 80
- Paper Size: US Letter
- Units: Imperial (feet and inches); main sizes also given in mm
- Dimensions: 12' x 8' coop and 16' x 8' run on a 28' x 8' base; 30' 1-1/2" L x 10' 1-13/16" D x 13' 1-5/16" H overall
- Style: Raised-center monitor barn with barn-red grooved panel siding, white trim and windows, an X-braced plank door and asphalt shingle roofs
- Skill Level: Intermediate
- Includes: 38 illustrated build steps, shopping list, master cut list, cut diagrams, panel layouts, roof framing templates, siding templates, elevations, floor plan and cross sections
- Best For: Backyard flocks of 15 to 20 hens
- Delivery: Instant PDF download after purchase, no physical item shipped

## What's Included in This Red Barn Chicken Coop Plan

The Thornbury is a walk-in chicken coop and covered run under one long monitor roof: a raised 12/12 center roof on two low clerestory walls, with a gentle 4/12 side roof on each side, like a classic raised-center farm barn. Eight small fixed windows in the clerestory band bring daylight deep into the coop, and over the run the band becomes a screened light strip.

- 12' x 8' walk-in coop with 85 sq ft of floor inside, 6' 8-1/2" of clear headroom under the ceiling ties and 11' 2-1/4" under the ridge in the raised center
- 16' x 8' covered run with 116 sq ft of ground, 7' 9-3/4" under the ties and a 35-1/2" x 73-3/4" walk-in run door
- Outside nest box on the back wall with 4 nests and a shingled lift-up lid for collecting eggs from outside
- Three roost bars with 199-1/2" of perch over a removable dropping board
- White X-braced barn door and a sliding pop door with a ramp into the run
- Three screened casement windows, 8 fixed clerestory windows, louvered vents and two rows of screened eaves
- Cedar-toned run frame with knee braces, wrapped in 1/2" hardware cloth with a buried apron against digging predators
- Estimated material cost of about $4,300 to $5,800 (prices vary by region and season)

## Monitor Barn Chicken Coop with Run for 15 to 20 Hens

The coop gives 4.2 to 5.6 sq ft per hen and the run 5.8 to 7.7 sq ft per hen, so this large chicken coop houses 15 to 20 chickens; the plan suggests some free-range time for the larger flock. The 4 nests follow the rule of one nest for every 5 hens.

## File Format, Paper Size and Measurements

The plan is an 80-page PDF on US Letter paper. All dimensions are in feet and inches for standard US lumber, with the main sizes also listed in millimeters. Every part has its own code that appears in the cut list, the cut diagrams, the templates and the step pages.

## Who This Walk-In Barn Style Chicken Coop Plan Is For

This is an intermediate build for DIY builders who are comfortable with a circular saw, a drill/driver and basic framing. Two people can build it in about 10 to 12 weekend days, plus painting. Spring is the busiest building season, so fall and winter are a good time to price lumber and prepare the site before new chicks arrive. It also makes a practical gift for a backyard chicken keeper.

## How to Use the Plan

1. Buy the plan and download the PDF.
2. Print the shopping list and the master cut list, or open them on a tablet.
3. Buy the lumber, panels, roofing and hardware.
4. Follow the 38 build steps in order, from the foundation blocks to the pop door and front step.

## Digital Product Note

This is a digital download. No physical item is shipped. The PDF is available for instant download right after purchase.

## Terms of Use

This plan is for personal use. You may build as many coops as you like for yourself. You may not resell, share or publish the PDF, its drawings or its renders, and you may not build coops from it for sale without written permission.

## Frequently Asked Questions

### What size coop do I need for 20 chickens?

A coop for 20 chickens needs about 4 sq ft of floor per hen inside plus run space. This plan gives 4.2 sq ft per hen in the coop and 5.8 sq ft per hen in the run at 20 hens.

### How much ventilation does a chicken coop need?

Ventilation in a chicken coop should stay open all year without drafts at roost height. This plan has 17.1 sq ft of always-open screened eaves, low on the walls and high on the clerestory, plus louvered vents and three screened windows.

### Why build a chicken coop with a monitor roof?

A monitor roof brings daylight into the middle of the coop through the clerestory windows and lets damp air escape high. It also gives full standing height under the raised center.

### Can I leave out the clerestory windows?

Yes. You can side the clerestory band closed, but keep the upper eave screens because they are the main way out for damp air.

### How do I download the PDF after purchase?

After checkout you get a download link on the order confirmation page and by email. Click it to download the PDF and save it to your computer, tablet or phone.

## More Building Plans from KRMPLANS

Browse the KRMPLANS shop for more chicken coop plans, sheds, greenhouses and cabins. If you have a question about this plan, send us a message and we will be happy to help.