12x20 Barn Shed with Side Porch - Free DIY Plans

This step by step diy project is about 12×20 gambrel shed with side porch plans. This shed features a gambrel roof and a side porch. In addition, you have an easy access to the interior using the double side doors or the front man door. You will also have plenty of light inside the shed, because it comes with 3 windows. You can use this shed for storage, or you can easily make a workshop for your creative endeavors. Make sure you read the local codes and make adjustments if necessary. Take a look over the rest of my woodworking plans, if you want to get more building inspiration.

When buying the lumber, you should select the planks with great care, making sure they are straight and without any visible flaws (cracks, knots, twists, decay). Investing in cedar or other weather resistant lumber is a good idea, as it will pay off on the long run. Use a spirit level to plumb and align the components, before inserting the galvanized screws, otherwise the project won’t have a symmetrical look. If you have all the materials and tools required for the project, you could get the job done in about a day. See all my Premium Plans HERE.

Projects made from these plans

12×20 Barn Shed with Side Porch – Free DIY Plans

Building-a-12×20-barn-shed-with-porch

Cut & Shopping Lists

A – 2 pieces of 2×6 lumber – 144″ long, 10 pieces – 141″ long FLOOR FRAME
A – 2 pieces of 2×6 lumber – 96″ long, 7 pieces – 141″ long FLOOR FRAME
B – 4 pieces of 4×4 lumber – 144″ long, 4 pieces – 96″ long SKIDS
C – 5 pieces of 4×4 lumber – 92 1/2″ long, 1 piece – 143 1/2″ long, 1 piece – 47 1/2″ long POSTS
C – 9 pieces of 5/8″x5 1/2″ lumber – 144″ long DECKING
D – 5 pieces of 3/4″ plywood – 48″x96″ long, 2 pieces – 48″x48″ long FLOOR
E – 2 pieces of 2×4 lumber – 96″ long, 1 piece – 89″ long, 8 pieces – 91 1/2″ long, 3 pieces – 37″ long, 2 pieces – 36″ long, 3 pieces – 7 1/2″ long, 4 pieces of 2×6 lumber – 27″ long FRONT WALL
E – 3 pieces of 2×4 lumber – 48″ long, 5 pieces – 91 1/2″ long FRONT WALL
G – 2 pieces f 2×4 lumber – 144″ long, 2 pieces – 56″ long, 11 pieces – 91 1/2″ long, 6 pieces – 37″ long, 10 pieces – 7 1/2″ long, 4 pieces – 36″ long, 8 pieces of 2×6 lumber – 27″ long, 2 pieces – 35″ long FRONT WALL
F – 1 piece of 2×4 lumber – 144″ long, 1 piece – 137″ long, 3 pieces – 91 1/2″ long, 1 pieces – 78 1/2″ long, 6 pieces – 7 1/2″ long, 2 pieces of 2×6 lumber – 75″ long SIDE WALL
H – 2 pieces of 2×4 lumber – 89″ long, 1 piece – 96″ long, 7 pieces – 91 1/2″ long SIDE WALL
I – 1 piece of 2×4 lumber – 233″ long, 2 pieces – 240″ long, 18 pieces – 91 1/2″ long BACK WALL
I – 15 pieces of 5/8″ T1-11 siding sheets – 48″x96″ long, 1 piece – 48″x16″ long SIDING SHEETS

19 pieces of 2×6 lumber – 12′
8 pieces of 2×6 lumber – 8′
5 pieces of 4×4 lumber – 12′
10 pieces of 4×4 lumber – 8′
9 pieces of 5/8″x5 1/2″ lumber – 12′
6 pieces of 3/4″ plywood – 4’x8′
80 pieces of 2×4 lumber – 8′
4 pieces of 2×4 lumber – 12′
3 pieces of 2×4 lumber – 20′
15 pieces of 5/8″ T1-11 siding sheets – 4’x8′
3 1/2″ screws
2 1/2″ screws
1 5/8″ screws
post base
rafter ties
wood glue, stain/paint, wood filler
6d nails

Tools

Hammer, Tape measure, Framing square, Level

Miter saw, Drill machinery, Screwdriver, Sander

Safety Gloves, Safety Glasses

Time

One week

PART 1: 12×20 Gambrel Shed with Side Porch Plans
PART 2: 12×20 Gambrel Roof Shed Plans

Building a 12×20 garden shed

Floor-frame-for-12×20-shed

The first step of the project is to build the floor frame. Drill pilot holes through the perimeter joists and insert 3 1/2″ screws into the perpendicular ones. Place the joists every 16″ on center and make sure the diagonals are equal.

Skids for large floor frame

Fit 4×4 skids under the floor frame. The skids will lift the floor from the ground to protect it from the elements. Invest in weather resistant because that will be much more durable than regular construction wood. Use rafter ties to secure the skids under the frame and lock them together with rafter ties.

Floor frame for shed

Next, you need to build the smaller section for the floor frame. Use 2×6 lumber, as well. Drill pilot holes through the rim joists and use 3 1/2″ screws to assemble everything tightly.

Fitting the skids – small floor frame

Fit the 4×4 skids under the floor frame, as well.

Fitting the skids – gambrel shed

Assemble the floor for the shed by drilling pilot holes and inserting 2 1/2″ screws.

Floor sheets – 12×20 shed

Use 3/4″ plywood sheets for the floor of the shed. Lay the sheets to the floor making sure you align the edges with attention and leave no gaps between them. Drill pilot holes through the sheets, every 8″ along the framing and insert 1 5/8″ screws.

Front-wall-frame-2

Continue the project by making the section walls for the storage shed with porch. Use 2×4 lumber for the plates and for the studs. Drill pilot holes through the plates and insert 3 1/2″ screws into the studs. Place the studs every 16″ on center. Frame a window opening so you can fit a 24″x36″ window. Use 2×6 lumber for the headers (sandwhich a piece of 1/2″ plywood between the headers and add glue and insert screws for extra bond).

front-wall-frame-1

Build the other section for the front wall of the barn shed, using the same techniques described above. Notice the double plates that will add strength to the shed structure. In addition, frame the front door for the shed, as shown in the diagram. I’ve also added 2 windows to the front of the shed for more light inside of the structure.

Narrow side wall

Build the third section for the front wall, as shown in the diagram.

Side wall frame

Use 2×4 lumber for the other side of the shed, as well.

Side-wall-with-double-doors-frame

Frame side wall with the opening for the double doors. Use the same techniques described above. Use 2×6 lumber for the double header. Fit a piece of 1/2″ plywood between the headers and add glue before inserting the 2 1/2″ screws, from both sides.

Back-wall-frame

Build the back wall for the shed in one or two smaller sections. Drill pilot holes through the plates and insert 3 1/2″ screws into the studs. Place the studs every 16″ on center.

Assembling-the-shed-frame-for-12x20-shed

Assembling-the-shed-frame-for-12×20-shed

After assembling the wall frames you need to lay them on the floor of the shed. Align the edges flush and plumb the walls with a spirit level. Drill pilot holes through the bottom plates and insert 3 1/2″ screws into the floor. Make sure the corners are square and lock the adjacent walls together tightly with 3 1/2″ screws.

Siding sheet – L shed

Use 5/8″ T1-11 siding sheets for the exterior of the shed. Align the edges flush then insert 6d nails, every 8″ along the framing.

Side wall with double doors siding

Fit the siding sheets to the side of the shed, as well. Make cuts around the door opening. Insert 6d nails to lock the panels into place tightly.

Side wall siding

Attach the siding sheets to the front of the shed. Make the cuts around the window openings and around the door opening.

Side wall siding sheets – barn shed

Fit the siding sheets to the other side of the storage gambrel shed.

Back wall siding sheets

Last but not least, attach the boards to the back of the garden barn shed.

12×20 Barn Shed with Porch – base

This is the main structure of the barn shed. as you can see in the diagram, everything is locked together tightly. The framing is done with 2x4s, but you can switch to 2x6s if you want to install insulation between the studs and use it as an workshop, even during the cold winter days.

Fitting the boards

Use 5/8″x5 1/2″ decking boards for the front porch. Align the edges with attention and leave no gaps between the decking boards. Drill pilot holes and insert 1 5/8″ screws to lock them to the joists.

Fitting the posts for the shed porch

Use 4×4 lumber for the porch posts. Cut the posts at 92 1/2″ and secure them to the deck with connectors. Plumb the posts vertically and lock them into place tightly.

Plates for porch

Use 4×4 lumber for the plates. Make notches to one end of the plates, as shown in the diagram. Use a circular saw to make parallel cuts inside the marked areas and clean the recess with sandpaper and a chisel.

Top rails for shed porch

Fit the plates to the top of the posts. Align the edges, drill pilot holes and insert 7″ screws to lock everything tightly. Make sure the corners are square and leave no gaps.

12×20 Barn Shed with Side Porch Plans

You need to take a look over PART 2 of the project, so I can show you how to build the gambrel roof and how to make the shed doors. In addition, I will show you how to assemble and install the railings to the shed porch.

12×20-barn-shed-with-porch-plans

Don’t forget that I have tons of free shed plans with step by step instructions. You can check all the plans HERE. I have lots of woodworking plans that cover everything from furniture up to playhouses. See the full list of plans HERE.

If you want to get PREMIUM PLANS for this project, in a PDF format, please press GET PDF PLANS button bellow. Thank you for the support.

This woodworking project was about 12×20 gambrel shed with side porch plans. If you want to see more outdoor plans, check out the rest of our step by step projects and follow the instructions to obtain a professional result.