13×20 Metal Shed: The Complete Buyer’s Guide for 2026

A 13×20 metal storage shed is a large outdoor building with 260 square feet of floor space, making it one of the most practical sizes for US homeowners who need substantial storage. At this size, a 13×20 metal shed functions as a genuine backyard building capable of housing a riding mower, ATV, and workshop tools simultaneously.

Why Choose a 13×20 Metal Shed Over Other Materials?

When you step up to a 13×20 shed, you are looking at a serious investment — typically ranging from $1,800 to $4,500 depending on steel gauge, roof style, and included features. At this price point, material choice matters more than ever. Metal sheds hold several key advantages over wood and resin alternatives at this size.

Durability and Longevity

A quality 14-gauge or 16-gauge galvanized steel 13×20 shed will last 15 to 25 years with basic maintenance. Compare that to wood sheds, which need repainting or staining every 2 to 3 years and are vulnerable to rot, termites, and warping. Resin sheds at this size are less common and typically cost more — a 13×20 resin shed from brands like Keter or Suncast can run $3,500 to $6,000.

Metal sheds handle snow loads well thanks to their reinforced roof panels. In northern states where winter snow accumulation hits 20 to 40 pounds per square foot, a properly anchored metal shed with A-frame or barn-style roof sheds snow naturally. Brands like Arrow and Best Barns design their large metal sheds with snow load ratings that meet or exceed local building codes.

Cost Comparison

Here is how the pricing shakes out for a 13×20 building:

• Metal shed: $1,800 to $4,500
• Wood shed (kit): $3,000 to $7,000
• Wood shed (built on-site, Tuff Shed style): $5,000 to $12,000
• Resin shed: $3,500 to $6,000

Going with metal saves you 40 to 60 percent compared to a comparable wood structure, and the gap widens when you factor in long-term maintenance costs.

Assembly Considerations for a 13×20 Metal Shed

This is where metal sheds earn their reputation — both good and bad. A 13×20 metal shed kit requires serious assembly. Figure 8 to 16 hours for two experienced people, or a full weekend for a DIYer working solo.

What You Will Need

A level foundation is non-negotiable at this size. You have three good options:

• Concrete slab — the gold standard. Costs $800 to $1,500 for a 4-inch slab with reinforcement. Adds permanence and prevents floor sag.
• Gravel base — the budget-friendly alternative. A 6-inch deep gravel pad with pressure-treated timber frame runs $300 to $600. Provides excellent drainage.
• Paving stones — a middle ground. Interlocking concrete pavers on compacted gravel cost $400 to $800 and allow future relocation.

Most metal shed manufacturers recommend a concrete slab or a treated lumber foundation for sheds over 120 square feet. For a 13×20, you will want a 14×21 base to allow clearance.

Tools needed for assembly include:

• Cordless drill with screwdriver bits
• Socket wrench set
• Rubber mallet
• Step ladder (you will need this for the roof)
• Utility knife
• Work gloves
• Level (at least 48 inches)
• Measuring tape

Common Assembly Pitfalls

• Not reading the manual cover to cover before starting. Read it first.
• Installing panels on uneven ground. Actually check with your level.
• Over-tightening screws, which strips the galvanized coating and leads to rust.
• Skipping the anchor kit. A 13×20 metal shed is a big sail in high winds.
• Forgetting to install drip edges on the roof, which causes water channeling issues.

Features to Look For in a 13×20 Metal Shed

Not all metal sheds are built the same. Here is what separates a good one from a frustrating one.

Steel Gauge

The gauge number tells you the thickness of the steel. Lower number equals thicker steel.

• 29-gauge: Too thin for a shed this size. Avoid.
• 26-gauge: Fine for mild climates. Common on budget sheds.
• 22-gauge: Good. This is what you should aim for.
• 20-gauge: Better. Found on premium models.
• 14 to 16-gauge: Best. Heavy-duty panels that resist denting.

For a 13×20 building, go with 22-gauge or thicker. Anything thinner feels flimsy at this span and may buckle under snow load.

Roof Style

• A-frame: Classic peaked roof. Best snow shedding. Most headroom inside.
• Barn style: Vertical walls with a lower peak. More wall space for shelving.
• Regular (gable): Simple sloped roof. Most affordable but less headroom.

For a 13×20, an A-frame or barn-style roof is ideal. The extra headroom makes the space feel larger and gives you room for wall-mounted shelving.

Door Configuration

Wide double doors — 5 to 6 feet wide — are essential for a shed this size. You will need to move a riding mower, wheelbarrow, or ATV in and out. Some 13×20 models offer sliding doors, which save swing space but can be slightly less weather-tight. Look for reinforced door frames — heavy doors sag over time on lightweight frames.

Floor Options

Some 13×20 metal sheds come with a built-in metal floor. Others are floorless and require you to build your own. A built-in floor saves assembly time but may not be as sturdy as a separate pressure-treated plywood floor. If the kit does not include a floor, budget $200 to $400 for materials.

Ventilation

Crescent vents near the roof peak prevent condensation buildup, which is the number one cause of rust inside metal sheds. Ridge vents are even better. If your chosen shed does not include vents, plan to add aftermarket turbine vents or gable vents. Skipping this step means dealing with rust spots inside within a few years.

Top Brands for 13×20 Metal Sheds

Arrow Storage Sheds

Arrow is the most recognized name in metal sheds. Their 13×20 models typically use 26 to 22-gauge steel with an A-frame roof. Arrow sheds are widely available at Home Depot, Lowe’s, and Amazon. Assembly is famously frustrating — plan for 12 to 16 hours. Expect to pay $2,000 to $3,500 for an Arrow 13×20.

Best Barns

Best Barns offers metal shed kits with thicker steel (22-gauge standard on many models) and better assembly manuals. Their 13×20 models often include built-in floors and more door options. Prices range from $2,500 to $4,000. Assembly time runs 10 to 14 hours.

Lifetime Sheds

While Lifetime is better known for resin sheds, they offer some large metal-frame resin hybrids. Their 13×20-equivalent models use heavy-duty steel frames with reinforced resin panels. These run $3,000 to $5,000 but offer the easiest assembly — typically 4 to 6 hours.

Yardistry

Yardistry focuses on wood-metal hybrid sheds with cedar and steel construction. Their large sheds run $3,000 to $6,000 and offer better aesthetics than all-metal options, but require more ongoing maintenance.

Permits and Zoning for a 13×20 Shed

Here is the reality check: a 13×20 shed is 260 square feet. Most US municipalities require a building permit for any structure over 100 to 200 square feet. You almost certainly need a permit for this size.

Typical permit requirements include:

• Site plan showing shed placement relative to property lines
• Setback requirements (typically 5 to 15 feet from property lines)
• Foundation inspection
• Roof load certification (especially in snow zones)
• Electrical permit if you plan to add lighting or outlets

Check with your local building department before purchasing. The cost of a permit ranges from $50 to $500 depending on your location. Failing to pull a permit can result in fines or being forced to remove the structure.

HOA restrictions are another consideration. Many homeowners associations limit shed size to 120 square feet or ban metal sheds entirely for aesthetic reasons. Review your CC&Rs before buying.

Where to Buy a 13×20 Metal Shed

You can find 13×20 metal shed kits at major retailers including Home Depot, Lowe’s, and online at Amazon. When shopping online, look for kits that include anchor kits and clear assembly manuals. For a wide selection of metal storage sheds, check our main catalog. If you need something slightly smaller, browse our medium storage sheds collection.

If you are ready to buy, check out a popular 13×20 metal shed option on Amazon here.

Frequently Asked Questions

Do I need a permit for a 13×20 metal shed?

In almost all cases, yes. A 13×20 shed is 260 square feet, which exceeds the typical 100 to 200-square-foot threshold that triggers permit requirements in most US cities and counties. Contact your local building department for specific requirements in your area.

How long does a metal shed last?

A quality 13×20 metal shed with galvanized steel panels and proper maintenance will last 15 to 25 years. The key factors are steel gauge thickness, quality of the galvanized coating, and whether the shed is kept dry with good ventilation. Rust typically starts at scratch points and fastener holes, so touching up scratches with galvanized paint extends the life significantly.

Can I insulate a metal shed?

Yes, and it is worth doing if you plan to use the shed as a workshop or spend time inside during extreme weather. Use rigid foam insulation panels between the wall framing, then cover with plywood or OSB. Avoid fiberglass batt insulation in metal sheds — it traps moisture against the steel and accelerates rust.

What is the best foundation for a 13×20 metal shed?

A concrete slab is the best option for a shed this size. It provides a level, permanent base that prevents the steel frame from twisting or sagging. A gravel base with pressure-treated timber frame is an acceptable budget alternative but may shift over time in freeze-thaw climates.

How much does a 13×20 metal shed cost?

Expect to pay $1,800 to $4,500 for the kit, plus $300 to $1,500 for foundation materials, $100 to $300 for an anchor kit, and $50 to $500 for a building permit. Total project cost: $2,250 to $6,800.

Final Thoughts

A 13×20 metal shed delivers the best bang for your buck when you need serious storage space. At roughly half the cost of a comparable wood shed and with a lifespan of 15 to 25 years, it is a smart investment for homeowners who need room for large equipment, workshop space, or bulk seasonal storage. The tradeoff comes in assembly time — budget a full weekend for two people — and the need for a proper foundation and permit.

Stick with reputable brands like Arrow or Best Barns, choose 22-gauge or thicker steel, and do not skip the foundation or anchor kit. A well-chosen and properly installed 13×20 metal shed will serve your property for two decades or more.

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