About
A pole barn drawn for your site
Most pole barn plans come in one size, drawn for loads you may not have. The Barn Planner starts from the building you need and the snow, wind and frost line where you build, places every post and member, and shows each check in green, amber or red with the rule behind it.
How it works
- 1
You set the building
Pole barn, horse barn, carport or shell; width, length, eave height, roof pitch and doors.
- 2
You set the loads
Snow, wind and frost line from your building department.
- 3
It frames the barn
Posts on footings, skirt boards and girts, trusses on every post line, purlins, bracing, doors and steel.
- 4
It counts the materials
Lumber packed onto the boards the yard sells, the trusses to order, steel panel by panel, trim, screws and concrete.
The method
Every rule in the planner comes from a source we read: the post-frame handbook from Cornell's NRAES, the National Frame Building Association, the building code, county post-frame guides, extension publications for horse barns and the steel makers' own specifications for their panels. 115 facts come from primary sources; each has an id that appears next to its check.
Green passes. Amber means read the note: the design is buildable, but it sits outside the range the prescriptive guides cover, for example snow above 30 psf or wind above 115 mph, and an engineer or the truss maker should look at it. A building wider than 36 ft, walls taller than 12 ft or bays over 8 ft get an information note instead, not an amber. Red has to change before the builder's plan is for sale.
Where the sources say nothing, we chose a value and call it our default: the window size, the stall board height and the thresholds for review. The purlins and door headers are checked as wood beams under your snow load; the trusses are always designed by the truss maker.
What it is not
The Barn Planner is a planning aid. It is not an engineered design, it does not know your soil or local rules, and it is not a substitute for your building department, the truss maker or an engineer. Check the plan with your building department before you build.
How the site is paid for
The designer and the free designs cost nothing and need no account. What pays for them is the builder's plan: a PDF for the exact building you design, with the post layout, every wall framed, the truss order sheet, the steel and the cut list, for $39 once. If our plan has an error, we fix it or refund you. The site carries no advertising.
Who runs it
The Barn Planner is an independent project operated by Westernmost LLC, 30 N Gould St Ste R, Sheridan, WY 82801, USA. If you find a mistake in a rule or a number, please tell us: a fix to the engine fixes every design at once.
Sources
Read on October 13, 2026.
- NRAES-1, Post-Frame Building Handbook (Cornell, NRAES): truss spacing, footing and embedment tables, doors, bracing.
- National Frame Building Association: post-frame design guide, treatment specification, truss sealing.
- AWPA U1: use categories for treated posts (UC4B) and skirt boards (UC4A).
- International Residential Code, R301, R317, R403.1.4.1, R905.10.2: loads, treated wood, frost protection, steel roof slope.
- County post-frame guides (Ohio RCO 328 summaries, Colorado, Missouri, North Carolina): prescriptive limits on width, height, snow and wind.
- Penn State and University of Kentucky Extension: horse stall size, aisle width, clear height, ventilation.
- Metal Sales, Union Corrugating and ABC: steel panel coverage, load tables, purlin spacing, minimum pitch.
Design the barn you need