Build Your Own 12X20 Gable Storage Shed With Ease!
The 3DSHEDPLANS 12x20 shed plans are for a gable storage shed 20 ft wide and 12 ft deep, with 240 sq ft of floor, 94 1/2" sidewalls and one window. The PDF has 40+ steps, 3D images, layouts and cuts, and a printable material list with quantities, from the skid foundation to the shingles.
Get the full plan PDF for $19.99 or download the free preview
Looking for a huge storage shed that would be reliable and easy to build? Look no further! With our 12X20 Gable Storage Shed Plan, you can build a spacious and mighty gable storage shed in less than 3 days. We have it all covered for you – right from the materials list to the step by step guidance and even 3D images. All you need to do is to start following the plan and have your gable shed ready in less than a week!

A Full-Fledge Material List with Required Quantity
The materials you use to build a shed are the secrets to your success. Unfortunately, most plans out there won’t precisely tell you what to buy and in what quantity. In fact, they would lure you to buy products from the plan-sellers. Luckily, we have a completely different motto. We want you to succeed in building your dream shed. And for that, we understand how important it is to get the right materials.
Our 12X20 Gable Storage Shed Plan comes with an all-inclusive list of materials, hardware and tools that you would need to build the shed. Nothing more, nothing less! No click baits! You get a printable list of materials that you can take to the hardware store. Did we forget to mention we have carefully only included materials that are light on your pocket and good in performance?

Simple, Easy to Understand Step by Step Instructions
Who would have ever thought to get their hands on a shed plan that would take them through the entire process with such ease! The 12X20 Gable Storage Shed Plan comes with easy to understand, step by step instructions for DIY newbies. Don’t worry if you don’t have any experience in building wooden structures. The plan you take you through without any complication jargons. Right from building the foundation to the walls and even the roofing, we have everything covered for you.

3D Rendered Images for Reality Check
2D images are a thing of the past! Our 12X20 Gable storage Shed plan comes with 3D rendered images, which means you get to see every corner, every angle and every inch clearly as if it is being right in front of you by a professional. You won’t have to scratch your head thinking how the shed should from the front, back or the sides. Even the rooftops are visualized in 3D for better understanding.
Building Your Own Shed vs. Getting Professional Help

You Save What a Builder Would Charge
Probably the most important reason for building your own shed is that you save money. A builder charges for labor on top of the materials, for work you can do yourself. With our 12X20 Gable Storage Shed Plan, you get clear instructions, material lists and diagrams to go through the process easily.

Choose Your Own Design and Make Your Dream Come True
Don’t fall for the marketing gimmicks of most professionals out there. When you start building your own shed, the world is out there for you to explore. With our material list and instructions, you will realize that you can build your dream shed without any design restrictions. The plan is simple yet it gives you the liberty to add in your own flavor!

You Will Reclaim Your House Again
The 12X20 Gable Storage Shed is spacious enough to fulfil your storage requirements. Whether you are a gardeners or an athlete, you can use the shed to keep all sorts of your equipment and tools. Besides, the shed will add an exquisiteness to your garden while fulfilling its purpose.

This Is Exactly What You'll Get with Your 12X20 Gable Storage Shed Plan!
- 40+ steps that expertly guide you through the whole process.
- Designed for beginners as well as for professionals.
- Explanatory 3D images so you can see exactly what to do next.
- Comprehensive materials list that gives you exactly what you need.
- Your plan will look great on any mobile device.
- Free PRO-TIP for every section.
- High quality PDF plan with everything you need emailed to you instantly.
- Shed Type
- Storage
- Roof Shape
- Gable
- Depth (ft.)
- 12'
- Width (ft.)
- 20'
- Depth (in.)
- 144"
- Height (in.)
- 142 3/4"
- Width (in.)
- 240"
- Exact Width x Depth
- 20' 8" x 12' 1"
- Sidewall Height (in.)
- 94 1/2"
- Number of Doors
- 2
- Door Type
- Single and Double
- Door Opening Height (in.)
- 76 1/2" and 82"
- Door Opening Width (in.)
- 36" and 78"
- Door Opening Height (ft.)
- 6' 4 1/2" and 6' 10"
- Floor Options
- 0.75" Tongue and Groove Plywood
- Number of Windows
- 1
- Recommend Roofing Material
- 7/16 OSB Sheet Board
How to Build a 12×20 Gable Shed in a Week or Less?
You don’t have to spend thousands of dollars asking construction companies to build your shed. We make building your own shed a lot easier and cheaper.
Welcome to 3DSHEDPLANS – with detailed shed building plans jotted down for you step by step on paper by professional woodworkers, building your shed was never this easy. You don’t need a professional shed builder or an expert woodworker. With our FREE and PREMIUM shed plans, you can build the shed on your own in less than a week by following our step by step instructions.
Follow our 10-step guide for a big 12×20 gable shed in your yard!
Step # 1: Check the Rules Where You Live
Rules for sheds vary by town. Check your local permit office before you build. Then decide on the following for your shed:
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What type of shed will you be building?
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Depending on the purpose, what will be the size of the shed?
Step # 2: Know what You Want: The Size & Type
The size and type of shed both depend on one prime thing: what do you want the shed for? If the shed is mainly for the purpose of storing tools, you might need a small shed, but if you plan on using it as your occasional hide out from the hassle of the home and vent out your creativity on canvass or paper, or alternatively turn into your mini garage, you might want to consider the bigger sizes. The 3 different types to choose from include,
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Lean-to Sheds: Compact and simple, the lean to sheds are made against the wall. Be it in your garden or your front or back yards, the lean-to-sheds are constructed from 3 sides. While they are easy to construct, they are smaller and could be used for storage purpose.
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Gable Sheds: A small room fit to be your escapade, the gable shed can easily be used for multiple purposes. It is easy to build and will prove not just as the storage spot for your garden and car tools but also a perfect getaway.
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Hip Roof Sheds: Exquisitely designed, hip roof sheds are complicated structures and are not advised to be constructed without a professional woodworkers help. They are large and can be used for multiple purposes.
Step # 3: Shopping: The Perfect Material & the Right Tool
With your size and type decided, 12 x 20 in your case, now you need to make a list and go shopping. You will need pressure treated timber, plywood, asphalt shingles, trusses & rafters, L joints, and headers etc. your basic tool list will include saw, hammer, galvanized nails/screws, screw driver, level, and wrench etc. In our PREMIUM 12 x 20 SHED PLAN, we will list down the exact measurements and quantities and make the shopping list for you instead making your job easier.
Step # 4: Measurements: Know the Height, Width, Length in all Dimensions
The last step before the actual construction begins is listing down your shed’s measurements. For a 12×20 shed, the foremost dimension to consider is the width and height of the front walls and side walls
Height: 12 feet and 2 ½ inches
Width: 20 feet and 1 inch
Sides Width: 12 feet and 1 inch
The top and bottom width of the side walls will differ because the top has to accommodate the roof beam as well.
In addition to these dimensions, you need to add door and windows to the shed. Since 12 x 20 is quite a big size, you might need 2 windows each 3×3 on the rear wall.
Step # 5: Construction Begins: Build Foundation, Make the Floor
With all the shopping done and dimensions figured out, start by laying the foundation of your shed. Make a skid foundation using pressure treated timber. Place the joists at even spacing and hammer them together using galvanize nails to make the base frame work. Use panel wood (tongue and groove plywood) to line the floor. You may use any alternate for flooring but panel wood is cost effective.
Dos & Don’ts:
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Don’t: Do not construct the foundation frame work anywhere else apart from where you plan on having your shed. It will not only be a trouble carrying the frame work around but movement will cause it to lose its sturdiness.
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Do: Clean up and ensure the ground where you are building your shed is clutter free, has no lose soil or vegetation that will affect the durability of the shed.
Step # 6: More Construction: Make the Walls
After finalizing the foundation and flooring, it’s now time to give your 12×20 shed some walls and bring it in shape. Again, use the pressure treated timber to create an evenly spaced framework of walls according to the mentioned dimensions. Cut space in the front and back walls according to the size of the door and windows. Join the wall frame work to the foundation and flooring using L-joints. For the outer cover of your walls, make use of T1-11 siding and hammer with galvanized nails.
Dos & Don’ts:
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Do: You might want to use temporary brackets to erect the wall structure on the foundation.
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Once the walls are fixed using nails, remove the brackets.
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Do: To install the door and window, follow the instructions given in the manual of the manufacturer
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Don’t: Do not expect guidance to install doors here, follow the manual with door manufacturers.
Step # 7: The Great Difficulty: Making the Roof Frame Work
Making the roof can be really tough because it involves difficult and varying measurements and includes a lot of heavy lifting. Here’s what you need to do to make the roof framework.
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Use pressure treated timber planks to make rafters for your roof.
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Nail the rafters at a 45 degree angle to make the trusses. Your trusses must all be identical.
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Fix the trusses on the wall studs using nails, screws and wall plates.
Step # 8: Covering the Roof: Shingles & Plywood
With the roof structure intact, you will now cover the roof using plywood and asphalt shingles. To install the shingles, read the manual from shingles manufacturers.
Step # 9: Finalizing the construction: Adding Trims and Soffits
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The foundation, floor and walls are ready; all you need now is a non-leaking roof. Add the trims keeping them flush with roof.
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With the trims done fix the fascia on the sides of your gable shed and install the soffits.
Step # 10: Adding Final Touches
Get the windows and doors as per the specifications and then install them on your structure following the reader’s manual. To add to your shed’s sturdiness and longevity, you may take the following measures.
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Cover the outside of your shed with lacquer or wood varnish to keep the plywood from falling a victim to the changing climates.
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You can also paint your shed on the outside, giving it a more aesthetic appeal.
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It is advised to insulate your shed properly to avoid any chances of short circuit.
That’s it! Your shed is ready in less than a week’s time and you can now go make all the possible use of that exquisite shed. However, if you need the accurate materials list, or you require particular details about the tools needed to construct this shed, the quantity of the materials used, you are recommended to download our FREE & PREMIUM GABLE SHED PLANS.
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12x20 shed plans: key specs
| Spec | 12x20 Gable Shed |
|---|---|
| Width x depth | 20' (240") x 12' (144") |
| Floor area | 240 sq ft |
| Overall height | 142 3/4" (11' 10 3/4") |
| Sidewall height | 94 1/2" |
| Door openings listed | 36" x 76 1/2" (single) and 78" x 82" (double) |
| Windows | 1 |
| Floor | 3/4" tongue and groove plywood |
| Roof sheathing | 7/16" OSB |
| Siding | T1-11 plywood |
| Roof covering | Asphalt shingles |
What you can fit in a 12x20 shed
At 20 ft long, a 12x20 shed is easy to split into zones:
- Storage end. Mower, wheelbarrow, bikes and seasonal gear near the door, with 6 ft shelving units along the walls under the 94 1/2" sidewalls.
- Work end. A workbench across the 12 ft end wall, with tools on a pegboard above it and the window for daylight.
- Long items. Ladders, lumber and pipe can hang on brackets along the 20 ft back wall.
Measure a riding mower or cart at its widest point against the door opening before you build.
What is on the 12x20 material list
The plan's steps name these materials, and the PDF list gives the quantity of each:
- Foundation and floor: pressure-treated skids, floor joists, 3/4" tongue and groove plywood.
- Walls: plates, studs, headers and T1-11 plywood siding.
- Roof: rafters, 7/16" OSB sheathing and asphalt shingles.
- Trim and hardware: trim, fascia, soffits, galvanized nails, screws and L-joint connectors.
- Tools: a tool list for the whole build.
The window is on the list as a prefabricated unit. Install it by the maker's instructions. Frame the rough opening to the size of the unit you buy.
What the plan includes
- 40+ step-by-step instructions, from the skid foundation to the walls, roof, trim, fascia and soffits.
- Full layouts, angles and cuts.
- 3D images of every side of the shed, including the roof.
- A pro tip for each section.
- A PDF emailed right after checkout that reads well on a phone.
Gable or hip roof for a 12x20 shed?
A gable roof has two slopes and a simple rafter layout, so it goes up faster and leaves open gable ends for vents. A hip roof slopes on all four sides and generally resists wind better, but takes more cutting (Building America Solution Center: hip roof vs gable roof). Same footprint with a hip roof: the 12x20 hip roof shed plan.
Before you build
- Permits. A 240 sq ft shed is large for a backyard, and size, height and setback rules vary, so check your local permit office first.
- Site and floor. Level the skids on compacted gravel or solid blocks, then measure both diagonals of the floor frame. When they match, it is square.
- Walls. A 20 ft wall frame is long and floppy. Raise it with a helper and brace it before you let go.
- Roof panels. The plan calls for 7/16" OSB on the roof. Read the stamp on each sheet for its span and exposure rating (APA: OSB), and keep the stack dry and off the ground until it goes up, since wood that stays wet decays faster (USDA Forest Products Laboratory Wood Handbook).
Related plans
- 4 ft shorter: the 12x16 gable shed plan V2 with a double door.
- Same 20 ft length, 2 ft shallower: the 10x20 gable shed plan.
- 4 ft deeper: the 16x20 gable shed plan.
- Against a wall: the 12x24 lean-to shed plan.
- Every gable shed plan in one place.
- See the style first: download the free 12x20 gable shed plan PDF.
- Pricing the build first? See the free lumber, sheet and hardware list for a 12x20 shed.
Shed building guides
- Shed Foundation on Frozen Ground: What Works and Costs
- 12×16 Hip Roof Shed Material List: Lumber, Sheets, Hardware
- 12×16 vs 10×20 Shed: Layout, Lumber, Permit Line
- 10×20 Shed Material List: Lumber, Sheets and Hardware
- Shed Roof Pitch: Minimum Slope and Best Pitch for Sheds
- 12×16 Lean-To Shed Material List: Lumber, Sheets, Hardware
Frequently asked questions
How much space does a 12x20 shed give you?
The 3DSHEDPLANS 12x20 gable shed is 20 ft wide and 12 ft deep, which is 240 sq ft of floor. The sidewalls are 94 1/2 inches and the shed is 142 3/4 inches tall overall.
Do the 12x20 shed plans include a loft?
The plan page does not list a loft. It is a single-story storage shed with a gable roof. Adding a loft changes the framing, so talk to a local builder before you change the plan.
What foundation does the 12x20 gable shed use?
The skids and floor joists are pressure-treated lumber, topped with 3/4 inch tongue and groove plywood. Clear plants and loose soil first, then frame the floor right where the shed will stay.
Is there a material list in the 12x20 plan?
Yes. The PDF lists the materials, hardware and tools for the whole shed with the quantity of each, ready to print. The window is on it too, as a prefabricated unit.
Can one person build a 12x20 shed?
Much of the cutting and nailing is one-person work, but raising 20 ft walls and setting roof framing needs a helper. The plan is written for beginners as well as pros.





