How to Build a Shed

Updated September 2026 · Home Project Resources

Before you buy a single board, call your local building department and ask two questions: what floor area is exempt from a permit, and what are the setbacks from the property line. Most jurisdictions exempt small accessory buildings, often somewhere between 100 and 200 square feet, but the number is genuinely local and nobody on the internet can tell you yours. Setbacks apply even to exempt buildings, so an unpermitted shed can still be an illegal shed.

Once you have those two numbers, the build itself is four stages: a flat, drained base, a framed floor and walls, a sheathed roof, and a door wide enough to be useful. The base is the part that decides whether the shed still works in five years.

Sizing lumber for the frame? Our board feet calculator converts your cut list into board feet so you can order lumber without guessing.

Updated September 2026

A note on numbers. You will not find a dollar figure on this page. Lumber, sheet goods, roofing, and delivered shed pricing move by region, by season, by yard, and by how the lumber market is behaving that month, so any printed range would be wrong for most readers and stale for the rest. What is here instead is the quantity math, the cut list, and the questions that let two lumberyard quotes be compared on the same basis.

How to build a shed, start to finish

1. Confirm the permit threshold and setbacks with the building department.
2. Pick the site for drainage, access, and sun, not just for what looks tidy.
3. Build the base and check it for level and square before anything else touches it.
4. Frame and deck the floor, then square the deck by measuring the diagonals.
5. Frame the walls flat on the deck, stand them, brace them, and tie them together.
6. Frame the roof, sheathe it, and dry it in the same day if you can.
7. Side, trim, and hang the door, then add the roofing.
8. Cut the vents and finish the grade around the base.

A first timer working weekends should plan on three to five full days for an 8x12 shed. A second person for wall raising day is worth more than any tool you could rent.

Check the permit threshold before you spend anything

This is the step people skip, and it is the only one that can force you to tear the shed down.

Typical exemption thresholds land in the 100 to 200 square foot range, which is why so many stock plans are 10x10 or 8x12. But "exempt from a permit" is not the same as "no rules apply." These usually still bind you:

• Setbacks. Minimum distance from side and rear property lines, often 3 to 10 feet.
• Easements. Utility easements can run through a back yard, and you cannot build over one.
• Maximum height. Frequently 10 to 15 feet for an accessory building.
• Lot coverage. The total footprint of all buildings as a percentage of the lot.
• HOA rules, which are separate from the town and often stricter about siding and roof color.

Two more that catch people. If you plan to run electricity to the shed, that almost always needs a permit and an inspection regardless of the shed's size, and in many places it needs a licensed electrician for the circuit at the panel. Do not improvise a buried extension cord. If you ever do work inside a panel yourself where that is legal, shut the breaker off and verify every conductor with a non-contact voltage tester before touching anything.

And call 811 before you dig. It is free, it takes a few days, and it exists because people hit gas lines with post hole diggers.

Shed foundation options compared

Four bases cover almost every DIY shed. Here is what each one buys, what drives its material order, and where each fails.

The gravel pad is the right default. Six inches of compacted 3/4 inch crushed stone in a pressure treated timber frame gives you drainage under the floor, a flat surface you can adjust, and a shed that stays dry underneath. Estimate the stone with our gravel calculator, and use the square footage calculator if your pad is not a simple rectangle.

Blocks on piers are cheap and fast, and they work when the ground is genuinely level and drains. The failure mode is settling: one block sinks half an inch in a wet spring and the door binds. If you use blocks, use solid concrete blocks, not hollow ones, and set each on its own bed of compacted gravel.

Skids are two or three pressure treated 4x6 timbers running the long direction with the floor built on top. Cheap, movable, and the standard for prebuilt sheds. They still want gravel strips under them, or the timbers sit in wet soil and rot.

A poured slab is the strongest and the most expensive of the four, and it is a commitment. It makes sense when you are parking a riding mower or running a real workshop. Work out the volume with our concrete calculator, and read concrete cost per yard for how ready mix is ordered, what a short load charge is, and which line items belong on a concrete quote.

Why the base matters more than the shed

Here is the failure people actually get, and it is almost never a collapsed roof.

The base settles unevenly. The floor frame twists a fraction of an inch. Walls are rigid boxes, so that twist travels straight up into the door opening. The opening goes out of square by a quarter inch and suddenly the door drags at one corner. You plane the door, it works for a season, the ground settles more, and it drags again.

That is racking, and it is why a shed sitting on four blocks that were "close enough" ends up as the shed nobody opens.

Three things prevent it:

• Get the base flat before you build. Not close. Use a long level on a straight board across the frame, or run a string line with a line level. Aim for within 1/4 inch across the whole pad.
• Square the floor deck by diagonals. Measure corner to corner both ways. On an 8x12 deck both diagonals should read about 14 feet 5 inches. Adjust until they match within 1/8 inch, then fasten.
• Let water leave. Slope the surrounding ground away from the pad, and extend the pad 4 to 6 inches past the shed on all sides so roof runoff lands on stone, not on dirt at the edge.

Framing the floor and walls

Floor. For an 8x12 shed, run pressure treated 2x6 joists 16 inches on center across the 8 foot direction, inside a 2x6 rim. That is nine or ten joists plus the rims. Deck it with 3/4 inch pressure treated or exterior grade plywood, glued and screwed. Half inch plywood flexes under a mower and telegraphs every joist line within a couple of years.

Walls. Frame each wall flat on the deck, then stand it. Standard framing works exactly like a house wall:

• 2x4 studs at 16 inches on center for anything you will hang shelves on, or 24 inches on center for pure storage.
• A single bottom plate and a double top plate, with the upper top plate lapping the corners to tie the walls together.
• Headers over the door and any window. A doubled 2x6 with a 1/2 inch plywood spacer handles a 4 foot opening in a shed easily.
• King studs full height on each side of an opening, jack studs under the header.
• Cripple studs above the header and below any window, keeping the 16 inch layout so sheathing seams still land on framing.

Build the two long walls first, stand and brace them, then the two short ones between them. Check plumb with a level on the corners before you nail the corners together, and leave the temporary diagonal braces on until the sheathing is up.

Sheathing. Half inch OSB or plywood on the outside is what actually makes the box rigid. Run the sheets vertically, stagger the seams, and nail the edges every 6 inches and the field every 12. Sheathing is the shear panel. Vinyl or metal siding over bare studs with no sheathing gives you a shed that leans.

Roof framing, pitch, and material

Most DIY sheds use one of two roofs.

A gable roof is two slopes meeting at a ridge. It sheds water well, gives you headroom and storage in the peak, and looks like a small house. Rafters are usually 2x4 at 24 inches on center for an 8 foot span, cut with a plumb cut at the ridge and a birdsmouth over the top plate.

A single slope roof, sometimes called a lean-to or skillion, is one plane. It is far easier to cut, it needs no ridge board, and it works well against a fence line or an existing wall. It costs you attic space.

Pitch matters more than style. Roof pitch is rise over 12 inches of run.

Aim for 4:12 or steeper if you are using asphalt shingles. Below 3:12, asphalt shingles are outside most manufacturer warranties, and the honest fix is metal panels or a rolled membrane instead.

Sheathe the roof with 1/2 inch OSB, add drip edge at the eaves, then underlayment, then the roofing. Get the underlayment on the same day the sheathing goes up. An overnight rain on bare OSB swells the edges and you will see the seams through the shingles forever.

Our roofing calculator will convert your roof dimensions and pitch into squares and bundles so you buy the right amount once.

Ladder safety, since a shed roof still puts you eight feet up. Set an extension ladder at a 4 to 1 angle, one foot of base for every four feet of height. Put it on firm level ground, never on the gravel pad you just poured until it is compacted. Keep three points of contact, never stand on the top three rungs, and keep your belt buckle between the rails instead of reaching sideways. If there is an overhead service drop anywhere near the shed site, keep the ladder and any metal roofing well clear of it.

Door sizing, and the mistake almost everyone makes

Make the door wider than feels necessary.

A single 32 inch door looks fine on paper and is miserable in practice. A push mower is about 22 inches wide but the handle is wider. A riding mower is 34 to 48 inches at the deck. A wheelbarrow with the handles is 26 to 30 inches, and you cannot angle it through a narrow opening while it is loaded.

Practical minimums:

• 48 inches of clear opening for a shed you will walk in and out of with tools and a wheelbarrow. Double doors at 24 inches each.
• 60 to 72 inches if a riding mower, a snowblower, or an ATV goes in.
• Frame the rough opening about 2 inches wider and 2 1/2 inches taller than the finished door unit, then confirm the number against the actual door you bought.

Two details that make a shed door last. Build or buy a door with a diagonal brace running from the bottom hinge side up to the top latch side, in compression, so it fights sag. And use three heavy strap hinges per leaf, not two, screwed into the framing rather than just the trim.

Add a small ramp at the threshold. A 2x8 sill with a beveled ramp board makes the difference between rolling a mower in and lifting it.

Ventilation, or why a sealed shed sweats

A tightly built shed with no vents will drip on the inside. Here is the mechanism: warm humid air gets in through the door every time you open it, the metal roof or sheathing cools fast overnight, and the moisture condenses on the coldest surface and rains back down on your tools. People blame a roof leak. It is not a leak.

The fix is cheap and it must be continuous, not occasional.

• Two vents minimum, high and low, on opposite walls. Low intake, high exhaust. Air moves because warm air rises, so a single vent does almost nothing.
• Gable vents in each end wall of a gable roof, or a continuous soffit vent plus a ridge vent.
• Rough target: about 1 square foot of net free vent area per 150 square feet of floor, split roughly half low and half high. For a 96 square foot 8x12 shed, that is a pair of vents totaling around 1 square foot of open area.
• Screen everything. Insects and mice will otherwise treat the vents as a front door.
• Do not skip a vapor path under the floor. A shed on a gravel pad breathes underneath. A shed set flat on soil or an unsealed slab pulls ground moisture straight up into the floor.

If you are insulating the shed for a workshop, the same rules that apply to a house apply here, and our insulation calculator will size the batts.

Worked example: the full material list for an 8x12 shed

An 8x12 shed is 96 square feet of floor, which sits under most permit thresholds and uses standard lumber lengths with little waste. Here is the complete take off for one built on a gravel pad with a 4:12 gable roof and 48 inch double doors. Hand this list to two lumberyards and you will get two quotes that describe the same shed, which is the only way to compare them.

How the stone number came out. The pad is 9 feet by 13 feet to overhang the shed by 6 inches on each side. That is 117 square feet. Six inches deep is 0.5 feet, so 117 x 0.5 = 58.5 cubic feet. Divide by 27 cubic feet per cubic yard and you get 2.17 cubic yards, call it 2.25 with compaction. Our gravel calculator does this for any pad size, and the square footage calculator handles odd shapes.

How to get comparable lumber quotes. Convert the framing list to board feet before you shop. A 2x4 at 8 feet is 5.33 board feet, and 70 of them is about 373 board feet. Our board feet calculator runs the whole cut list at once so two yards are quoting the same volume of wood rather than two different guesses at your shed.

Then ask each yard the same four questions, because these are where two quotes on the same list stop matching: what grade and species is the framing lumber, is the treated stock ground contact rated or above ground only, is delivery included and to where on the property, and is the sheet goods count based on your list or theirs. A quote that is lighter than the other usually differs on one of those four rather than on the price of wood.

Kit versus build from scratch versus prebuilt delivered

There are three honest ways to get a shed, and the right one depends on what your time is worth.

Build from scratch wins on outlay and on quality for what you spend. You control the floor thickness, the door width, and the roof pitch. It loses if you do not already own a circular saw, a drill, a level, and a way to make repeatable cuts.

A kit buys you a cut list that is already correct and a set of instructions. That is worth a great deal on your first shed. Read the spec sheet carefully: many kits exclude the floor entirely, use 7/16 inch siding as the only wall skin, and assume you have already built a level base.

Prebuilt delivered is the fastest path and often the best value once you count your own weekends. The truck arrives, a mule drives the shed off, and you are done in an afternoon. Two conditions decide it: the delivery route needs roughly 12 feet of clear width and a reasonable slope, and you still need a level base ready before the truck comes.

One more note on quality. Compare wall studs at 16 versus 24 inches on center, floor decking thickness, and whether the roof is real sheathing or a thin panel. Those three items separate a shed that lasts 25 years from one that sags in eight.

Where a shed build touches other projects

If you are already comfortable with framing, the skills transfer. Our how to build a deck guide covers ledger flashing, joist layout, and footing depth in more detail, and the frost depth discussion there applies to shed piers too. If your shed lands near a property line, how to install a fence covers locating the line and setting posts without a boundary dispute.

A note on older sites. If you are demolishing an existing shed to make room, assume painted surfaces from before 1978 may contain lead and that older sheet siding, roof panels, or floor tile from before about 1990 may contain asbestos. Do not sand, grind, or power wash suspect material. Test it or have a licensed abatement contractor handle it.

Frequently asked questions

What size shed can I build without a permit?

It depends entirely on your jurisdiction. Exemptions commonly sit somewhere between 100 and 200 square feet of floor area, which is why 10x10 and 8x12 are such popular sizes, but plenty of places set it lower or add a height cap. Call your building department, ask for the accessory structure threshold and the setbacks, and get the answer in writing if you can.

What is the best foundation for a shed?

For most sheds on most sites, a compacted gravel pad inside a pressure treated timber frame. It drains, it can be leveled precisely, it is the cheapest of the four bases once you count labor, and the shed can still be moved later. A poured slab is better only if you are putting heavy equipment or a real workshop inside, and it permanently fixes the shed in place.

Does a shed need a concrete slab?

No. A slab is one option, not a requirement, and for a storage shed it is usually the wrong one. Concrete holds moisture against the bottom plate unless it is properly sloped and sealed, it costs three to five times what gravel costs, and it removes the option to relocate the shed. Gravel with a framed floor above it keeps the wood dry and drains better.

How high should a shed floor sit above the ground?

At least 4 inches, and 6 is better. That gap keeps splashback off the siding, lets air move under the floor, and stops the frame from sitting in wet soil. Extend the gravel pad a few inches past the walls on all sides so roof runoff hits stone rather than digging a trench at the base.

What roof pitch should a shed have?

4:12 to 6:12 for a shingled shed. That is enough slope to shed water and snow, steep enough for standard asphalt shingle warranties, and shallow enough to work on safely. Below 3:12 you should switch to metal panels or a membrane roof, because water moves too slowly across a shallow shingle roof and finds its way under the tabs.

How wide should shed doors be?

Wider than you think. 48 inches of clear opening is the practical minimum for anything you will roll a wheelbarrow through, and 60 to 72 inches if a riding mower or snowblower lives inside. Nobody has ever regretted a wider shed door. Plenty of people have rebuilt a wall to widen one.

Do sheds need ventilation?

Yes, and it is not optional in a humid climate. Without vents, warm moist air condenses on the cool underside of the roof overnight and drips on everything below, which people usually mistake for a leak. Put a low intake vent and a high exhaust vent on opposite walls, roughly 1 square foot of open area per 150 square feet of floor, and screen both.

Is it cheaper to build a shed or buy one?

Building from scratch is the cheapest of the three on outlay, because you are buying materials and nothing else, but it costs you three to five full days and assumes you already own the tools. A prebuilt delivered shed is the most expensive and takes an afternoon. Kits sit in the middle on both counts. The honest way to decide is to get one delivered quote and one lumberyard quote on the cut list above, take the difference, and divide it by the days the build would take you. That gives you a daily rate for your own weekends, and only you can say whether it is worth it.

The short version

Call the building department first, because floor area exemptions and setbacks are local and they are the only thing that can force a teardown.

Then spend your effort on the base. A compacted gravel pad inside a treated timber frame, flat within a quarter inch and squared by matching diagonals, is what keeps the door closing in year five. Everything above it is ordinary framing: 2x6 floor joists, 2x4 walls with sheathing for rigidity, and a 4:12 or steeper roof dried in the same day it goes up.

Make the door 48 inches or wider, add a low vent and a high vent on opposite walls, and run the numbers before you shop. Our board feet calculator sizes the lumber order, the gravel calculator sizes the pad, and the roofing calculator sizes the shingles.