How to Build an Attached Shed


Building on a shed for firewood, lawn tools or yard toys is a great way to add value to your outdoor space. Using an existing wall for support simplifies the project and saves time and money on materials. Choosing siding and/or paint that matches the existing structure can help to blend it into the architecture, making your shed a beautiful addition to your house, garage or barn.

Cutting Your Shed Pieces

Step 1

Using a circular saw, cut a shed bottom from 3/4-inch plywood, 24 x 48 inches. Cut a roof 28 x 52 inches.

Step 2

Cut a shed front 54 x 48 inches from 3/4-inch exterior siding plywood from any lumber yard or home center. Mark one 48-inch end as the top. Draw a rectangle, centered in the bottom edge 30 inches wide by 50 inches tall. This is your door. Using a circular saw, cut the left edge of the door halfway up. Attach two 2-inch utility hinges evenly spaced spanning this cut. Cut the remaining half of the left edge, adding two more hinges, evenly spaced. Cut the right side of the door, leaving the top uncut.

Step 3

Cut shed ends out of your siding. Cut two pieces 24 3/4 inches x 60 inches. Mark a point six inches from one corner along the long edge on one piece. Draw a line from this mark to the opposite corner of the 24 3/4-inch side closest to the mark. Cut along the line to create a half gable. Repeat with the remaining piece .

Step 4

Cut two 2 x 4s, 55 inches long; cut two 21 inches long; cut three 48 inches long.

Assembling Your Shed

Step 1

Build a rectangular frame 24 x 48 inches with two 21-inch and two 48-inch 2 x 4s. Fasten frame corners with 3-inch treated deck screws. Screw the shed bottom to the top of this frame using 1 1/4-inch screws. Your shed base is complete.

Step 2

Attach the shed front to the half gables along their 54-inch front edges, with the outside of the siding facing out. Set the front inside the gables, flush with the front edges. Use 1 1/4-inch screws to fasten the joints. Place shed base inside this shell. Attach with 1 1/4-inch screws.

Step 3

Add the 55-inch 2 x 4s in the open back corners. Stand the 2 x 4 on end, flush with the open back of the shed. Attach the 1 1/2-inch edge to the gable end using 1 1/4-inch screws.

Step 4

Add the remaining 48-inch 2 x 4 at the top of the open back end. Place the 1 1/2-inch edge on top of the two corner 2 x 4s. Screw through the gables into the 2 x 4 using 3-inch screws. Reinforce corners with L brackets.

Step 5

Attach the shed to the side of the house by screwing through the top 2 x 4. For vinyl or wood siding use treated deck screws. For brick or masonry use tapcon-style concrete anchors. Follow manufacturer's instructions for installation. Add the roof. Attach by screws into the top 2 x 4 and the gable ends.

Things You'll Need

  • 1 sheet 3/4-inch plywood
  • 2 sheets 3/4-inch exterior plywood siding
  • 8 8-foot 2 x 4s, treated
  • Circular saw
  • Tape measure
  • Drill and treated deck screws
  • Tapcon anchors (optional)


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Keywords: buld an attached shed, building on a shed, making your shed

About this Author

Mark Morris started writing professionally in 1995. He has published one novel and four stage plays with SEEDS studio. Mark specializes in many topics and has 15 years of professional carpentry experience. He is a voice, acting and film teacher. He also teaches stage craft and lectures on playwriting for Oklahoma Christian University.

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