Firewood Shed Plans: Sizes and Cord Capacity

Firewood shed plans start with one number: how many cords you want to keep dry. A cord is 128 cubic feet, a stack 8 ft long, 4 ft wide and 4 ft high (University of Kentucky Cooperative Extension). The floor, the roof height and the number of bays all follow from that stack.

Our designer draws enclosed storage sheds, not wood sheds, so we have no firewood plan to hand you. What we have is four free lean-to plans that make a good frame, roof and materials list. This guide works out how many cords each one holds, lists the materials for the two smallest, and says what to change to turn a closed lean-to into an open, airy wood shed. It also points to EPA’s free plan, which is a real firewood shed.

Firewood shed plans: what the designer gives you

The closest free plan

The designer has four lean-to presets, named width by depth: the 8x4, the 8x6, the 10x8 and the 12x8. Each is a single-slope shed with the tall wall at the front and the roof falling to the back at 3/12. The 8x4 is the plan people search for as a “4x8 firewood shed”: 8 ft wide and 4 ft deep. Every plan page carries the cut list and the shopping list.

What it does not draw

The designer draws a shed with a wood floor, four walls and a door opening. It has no firewood mode: no open front, no slatted sides and no option to leave the siding off. So read “plan” here as a frame, roof and materials starting point. Everything in the section on what to change is our reasoning, not a setting on the plan page. The door is only an opening with a header, and the designer does not size a beam for a fully open front.

The free EPA plan

If you want a real firewood shed drawing, EPA has one. The Burn Wise flyer “Build a Firewood Storage Shed” says the shed “Holds about one cord of wood” and “Takes two people about 5 hours to build”, and it includes a materials list. It credits the Makah Tribe’s modular wood shed design. The Burn Wise program ran from 2009 to 2025, and EPA now calls its website a historic record, so the page is no longer updated. It still explains the parts well. We compare it with the 8x4 preset below.

How big should a firewood shed be

A cord in cubic feet

A cord must equal 128 cubic feet, says the California Department of Food and Agriculture, and you measure it by stacking the wood neatly in a row with the pieces touching. The University of Arkansas Division of Agriculture says the same, “By law, a cord must equal 128 cubic feet.” Kentucky gives the shape: 8 ft long, 4 ft wide and 4 ft tall. Check it: 8 x 4 x 4 = 128.

Two side facts change how you size a shed. First, “face cord” is not a legal unit. California’s weights and measures office says the term has “no legally defined meaning”. Arkansas describes a face cord as a stack 4 ft high and 8 ft long with pieces shorter than 4 ft, typically 16 inches, which is one third of a cord. Second, a cord is mostly air. Arkansas says the solid wood in a cord averages about 85 cubic feet and that the rest is airspace. Your shed has to hold the air too.

How many cords you need

Kentucky Extension says a home will need about 3.5 cords to get through the winter, and calls that a middle of the road estimate, because the amount of wood depends on the heat it gives and on the stove. Your own burn decides. Count what you used last winter, add the wood you want seasoning for next year, and size the shed for that total.

The quick size rule

Divide the cords by the stack height to get floor area. Cubic feet = cords x 128, and floor area in square feet = cubic feet / stack height in feet.

• 1 cord at a 4 ft stack: 128 / 4 = 32 sq ft of stacking floor.
• 2 cords at a 4 ft stack: 256 / 4 = 64 sq ft.
• 3.5 cords at a 4 ft stack: 448 / 4 = 112 sq ft.

That is the floor under the wood, not the floor of the shed. The walls take some, and so do the air gaps. The next section puts real inside sizes on it.

Firewood shed plans by cord: the four lean-to presets

Inside sizes

The designer frames walls with 2x4s, 3-1/2 inches thick. The front and back walls each take 3-1/2 inches of depth and the side walls each take 3-1/2 inches of width, so the inside is the outside size minus 7 inches each way. The wall heights come straight from the designer’s output for each preset.

The low wall is the back wall. The roof slopes down to it, so it caps how high you can stack there. A 5 ft stack is 60 inches, which leaves 14 inches under the lowest plate of the 10x8 and 12x8. A 6 ft stack would leave 2 inches, which is too tight to load. That is our planning judgment, not a rule from a source.

The stack arithmetic

Multiply the inside width, inside depth and stack height in inches, divide by 1,728 to get cubic feet, then divide by 128 to get cords. For the 8x4 stacked 4 ft (48 inches) high: 89 x 41 x 48 = 175,152 cubic inches. That is 101.4 cubic feet, or 0.79 cord. At 5 ft (60 inches) it is 89 x 41 x 60 = 218,940 cubic inches, 126.7 cubic feet, 0.99 cord.

These are ceilings. They assume the wood fills the whole floor from wall to wall, with no aisle and no air gap. Real stacks hold less.

Rows of 16 inch wood

Wood stored in rows gives a more honest number. A row of 16 inch pieces along the 89 inch inside width of the 8x4, stacked 4 ft high, is 89 x 16 x 48 = 68,352 cubic inches, 39.6 cubic feet, 0.31 cord. That is close to a third of a cord, the face cord shape Arkansas describes. Rows that fit the inside depth: 41 / 16 = 2.6, so 2 rows.

Rows leave a little of each floor unused, and the 10x8 lands a hair under two cords at 4 ft. Stack it 5 ft high and the same five rows hold 251.1 x 1.25 = 313.9 cubic feet, 2.45 cords.

One cord, two cords and three

• 1 cord. The 8x6 holds 1.26 cords in rows at 4 ft high, so it clears one cord with room for gaps. The 8x4 gets to 0.99 cord only when packed 5 ft high, so treat it as a three-quarter cord shed.
• 2 cords. The 10x8 holds 1.96 cords in rows at 4 ft and 2.45 at 5 ft. Choose it if you want two cords with a margin.
• 3 cords. The 12x8 holds 2.38 cords in rows at 4 ft and about 3.31 cords packed at 5 ft. Kentucky’s 3.5 cord estimate for a home is a little more than it holds, so a second bay or a custom size in the shed designer is the way to go.

4x8 firewood shed plans: EPA’s shed and the 8x4 preset

EPA’s flyer gives the parts of its one-cord shed. The back is four 1x4 slats 89 inches long, the sides are eight 1x4 slats 45 inches long, and the frame is two 2x6 boards 8 ft long. Posts stand at the front and the back, with the rear ones shorter so the roof slopes. The roof is one 4x8 sheet on six 2x4 rafters, and six 12 inch concrete deck blocks carry the floor.

Take the slat lengths as the open space, 89 by 45 inches. At 4 ft high that is 89 x 45 x 48 = 192,240 cubic inches, 111.3 cubic feet, 0.87 cord. At 5 ft it is 139.1 cubic feet, 1.09 cords. That fits EPA’s “about one cord”, and it says the designer’s 8x4, at 89 by 41 inches inside, is about 4 inches shallower.

For a 4x8 firewood shed on a small lot, either works. The EPA design has an open front and no siding, so it is lighter. The 8x4 preset gives you a real roof frame, a 2x6 rafter for each 16 inches, and a cut list.

Lean-to wood storage shed: what to change from the preset

Open front, slatted walls

A wood shed keeps wood dry, not warm. EPA says to store wood outdoors, off the ground, “with only the top covered”, because “covering the sides traps in moisture”. Kentucky says the stack should be raised for “full air circulation”. So on the preset you drop the siding, and you keep the roof.

• Skip the siding. The 8x4 shopping list has 9 siding sheets, and the 8x6 has 11, plus Z-flashing for the joints. A wood shed does not need them.
• Open the front. The high front wall has a 36 inch door opening. For a wood shed, swap that wall for posts, as in EPA’s flyer, and get a beam sized for the span from your building department or a supplier.
• Slat the back and sides. EPA’s flyer uses 1x4 slats on the back and sides. Leave gaps between them so air moves through.

The floor and the base

Kentucky says the stack should sit four to six inches off the ground. On the designer’s skid floor, the top of the subfloor is 11-3/4 inches above the pad: a 4x6 skid, 2x6 joists and a 3/4 inch subfloor. That clears Kentucky’s four to six inches by a wide margin, and the skids are pressure-treated for ground contact. A gravel pad drains the base; our gravel shed base guide covers the size and depth.

The roof

The preset roof is 3/12 with asphalt shingles, and the designer warns that at that pitch shingles need two layers of underlayment. The 2021 IRC, R905.2.2, is the model code behind that: shingles only from 2:12, with double underlayment from 2:12 up to 4:12. The locally adopted edition decides. Our shed roof pitch guide explains the pitches, and the metal roof guide covers the other covering.

EPA’s improvement note says to extend the shed roof a foot on all sides to protect the wood better. The designer’s overhang field runs from 0 to 12 inches, so set it to 12. This 8x6 lean-to with a 12 inch overhang is the starting point. If you would rather add a wood bay to a shed you already own, the lean-to on a shed guide shows how.

Materials for the 8x4 and 8x6 lean-to presets

This is the shopping list from the designer for the closed sheds, as they are drawn, with no prices. The siding and Z-flashing rows are the ones a wood shed drops. The tall front wall is 97-1/8 inches, so its siding is two 4x8 panels stacked with a horizontal joint on Z-flashing over 2x4 blocking. Quantities are the designer’s, with its waste allowances included.

The 8x4 has seven 2x6 rafters at 63-1/4 inches, and the 8x6 has seven at 87-15/16 inches, and both stand 9 ft 8-1/2 inches tall overall. The designer’s checks pass on both: the rafters, the floor joists and the door header all come out with spare capacity.

A wood shed does not need the trim boards or the siding nails either, and the studs on the open front wall turn into posts. Read the plan page for the full piece list, and open the designer with your own numbers to change the depth.

How to build a firewood shed

The steps are general practice. For the framing, the lean-to shed guide goes into each one.

1. Pick the spot. Choose ground with sun and open air. Kentucky says not to stack in perpetual shade, because sunlight speeds drying. Kentucky also says drying or storage stacks should be at least 30 feet from any structure, to avoid a fire hazard, so ask your fire marshal or insurer before you build against the house.
2. Level a base. Lay a gravel pad a foot wider than the shed on each side, or set blocks. Call 811 before you dig.
3. Frame the floor. On the preset, that is three 4x6 skids and 2x6 joists at 16 inches on center. On EPA’s version, it is a 2x6 frame on deck blocks with slats.
4. Raise the walls. Frame the low back wall and the two sides. Set posts or a beam on the open front.
5. Roof it. Set the 2x6 rafters at 16 inches on center, sheath with OSB and cover it with shingles or metal.
6. Slat the back and sides. Screw 1x4 or 2x4 slats with a gap between them, as EPA’s flyer does with its back and side slats.
7. Stack the wood. Split it, stack it in rows, and keep the top covered.

Stacking, seasoning and where the shed fits

A shed stores wood. It is not always the fastest way to dry it. Arkansas says to pile wood fuel in single rows exposed to the sun and wind, and to keep it drying for six months or longer. EPA says to season for at least six months. Kentucky says six months minimum and a year preferred, so next year’s wood is cut while this year’s burns.

Dry wood matters because wet wood burns badly. EPA says wood burns best at a moisture content of less than 20 percent and to test it with a moisture meter. Arkansas gives the same 20 percent and says seasoning takes six to nine months. So a good plan is to split and season wood in an open single row, then move it into the shed for storage.

A firewood shed is still a shed. Its size, its height and how far it sits from your lot line are set by your town, not by the plan, so read our shed permit basics and call the building department. The how to build a shed guide has the full build order, and the plans page lists every free size.