About

A plan drawn to your size

Most free shed plans come in one size, and the moment you change anything the cut list is wrong. The Shed Planner starts from the size you type: it frames every wall, sizes the rafters and joists for your snow load, checks the spans, then counts every board and sheet. Change the shed and every drawing and every number change with it.

How it works

1
You set the size
Width, depth, roof, wall height, doors, windows, foundation, spacing and snow load.
2
It frames the shed
Every wall is laid out stud by stud with plates, headers, jacks, kings and cripples, the way a framer would.
3
It checks the lumber
Rafters, floor joists and bearing headers are checked for bending and deflection before a size is picked.
4
It builds the lists
A materials list optimized for standard board lengths, with sheet goods, roofing and fasteners, free on screen. The $29 builder's plan adds the cut list with every cut assigned to a board.

The method

The framing follows standard light-frame practice for small wood buildings: a bottom plate and a double top plate, studs on a 16 or 24 inch layout measured from the building corner so panel edges land on studs, king and jack studs with a doubled header over every opening, corner backer studs, and a cap plate that laps the corners.

Lumber sizes are checked, not guessed. For rafters the planner uses design values for Spruce-Pine-Fir No. 2 from the National Design Specification for wood construction, with your snow load plus 10 psf of dead load, and requires both the bending stress and the deflection (span divided by 180, or by 240 on roofs of 3/12 and flatter, as the model code's deflection table asks) to stay within limits. On a standard 8x10 gable shed that makes a 2x6 rafter good for about 11' 11-1/8" of horizontal span at 16 inches on center and 30 psf of snow, against the 47-1/4" it actually spans. Floor joists and headers in bearing walls are checked the same way.

The buy list is worked out by fitting every cut into standard 8, 10, 12 and 16 ft boards (members longer than 16 ft are spliced over supports unless you choose 20 or 24 ft boards; a lean-to rafter over 16 ft is never spliced), plus precut studs where the wall height matches, choosing the board length that leaves the least waste each time and the shorter board when two come out even. Trim boards are bought in 8, 12 or 16 ft; every piece is cut whole, short pieces share a board when they fit with no joint, and runs longer than 16 ft meet at a butt joint over a rafter.

What it is not

The Shed Planner is a planning aid. It does not know your soil, your wind exposure, your frost depth or your local amendments to the building code, and it is not a substitute for an engineer or for your building department. Check the plan against your local rules before you build, and read our permit basics guide for the questions to ask.

Who runs it

The Shed Planner is an independent project operated by Westernmost LLC, 32 N Gould St, Sheridan, WY 82801, USA. The designer and the 20 preset plans are free to use for your own shed; a builder's plan for your own design is $29, one time. We do not sell your data, and there is nothing to sign up for. If you find a mistake in a plan or a guide, please tell us: every correction goes into the engine, so it fixes every size at once.

The front wall of an 8x10 gable shed, framed by the planner with a 48" door opening.

Try it on your size

Open the shed designer