DIY 16x20 Gable Storage Shed Plan

The full plan is $19.99: buy the 16×20 gable shed plan. To see the drawing style first, open the free 16×20 gable shed plan PDF, an 8-page preview.

The 16×20 shed material list, stage by stage

The shopping list is split by stage, so you can buy the foundation and floor first and the roof later, and each line is in the stock length that wastes the least. These are the big lines, copied from the plan:

The longest board on the list is 16 ft, so a standard delivery covers it. Add 2 or 3 spare studs for bad boards, as the plan suggests. The temporary braces and the ridge post are in the totals and can be reused after the build. The 1×4 filler strip is there because 4 rows of tongue and groove sheets cover 15′ 10″ of the 16 ft floor; you rip it to 2″ and glue and screw it along the back rim.

16×20 gable shed: the numbers for a site check

Square the stakes to matching 25′ 7 3/8″ diagonals before the stone goes down, and mark the roof footprint, not just the walls, when you check the yard. The ramp reaches out in front of the door, so leave room there.

How the 16×20 shed goes together

Building 20 ft long from 16 ft stock

• Skids. Each 20 ft skid is an 8 ft and a 12 ft piece butted on the gravel, the joint under a floor joist, scabbed on both sides with a 3 ft pressure-treated 2×4 and kept 4 ft or more from the joint in the next skid.
• Rims. Each rim is cut 9′ 4 3/4″ + 10′ 7 1/4″ and breaks over a doubled joist.
• Ridge. The 20′ 8″ 2×8 ridge is 9′ 8″ + 11′ 0″, the joint centered on the rafter pair 9′ 4″ from the left corner and held on a temporary 2×4 post, 11′ 7 1/4″ from the deck to the underside of the ridge, until that pair is nailed. Then a 24″ 2×4 cleat ties the joint.

The nailed floor frame weighs about 680 lb, so the plan has you build it in place on the skids and square it there.

How the walls go up

Each wall is framed flat on the deck and raised as a bare frame, and the siding goes on after all four stand. The two 20 ft walls go up in two sections each, so two people can raise every lift.

• Hinge it. Drive two or three nails partly through the bottom plate into the deck at the tipping edge so the section pivots instead of sliding.
• Brace at once. Never leave a raised wall unbraced, even for a minute, and never raise one in gusty wind.
• Hanging the siding. Screw a straight 2×4 ledger to the floor frame at the siding’s bottom line, stand each sheet on it, have your helper hold it plumb while you tack the top corners, then nail it off.

What you can fit in a 16×20 shed

The plan includes a to-scale drawing of one way to fill the floor:

• A riding mower. The door opening is 72″. A 42 in deck mower is 55.2″ wide and 5′ 10″ long, and parks nose in with the 72″ opening clearing each jamb by about 8″.
• Shelves and a bench. 24″ deep shelves run along the back wall, 16″ deep shelves along the back 6 ft of each side wall, and a 20″ deep bench sits under the right window.
• The rest of the yard gear. A wheelbarrow (2′ 2″ x 5′ 0″) and two bikes with their handlebars staggered fit beside the mower.
• A small lip, not a step. The floor sits 9 3/4″ up, and the ramp ends about 13/16″ below the deck.

Stick-framed rafters vs trusses on a 16×20 gable roof

This 3DSHEDPLANS plan frames the roof with 32 2×6 rafters 16″ on center against a 2×8 ridge board, plus 4 fly rafters, so two people can build it one pair at a time with no truss jig. The rafters rise 4′ 4″ from the top of the walls to the top of the ridge.

• One pattern. Cut one rafter with a 3 1/2″ seat and a 1 3/4″ heel, test it on both sides, then trace the rest. Each rafter comes from its own 12 ft board, 10′ 2 11/16″ overall.
• Ridge first. A 3′ 8 3/4″ center stud on each gable wall carries the ridge pieces while you set the end pairs, then the pair at the ridge joint, then the others.
• Ties. A 16 ft 2×4 rafter tie sits on the plates beside each of the 14 interior pairs, and 7 collar ties go on every other pair, their tops 2′ 10 11/16″ above the plates.
• Connectors. Each rafter gets a hurricane tie at the plate; the 4 end rafters at the corners get framing angles.
• Venting. Air comes in through 8 screened soffit vents and a 2″ screened slot over each beveled frieze block, and leaves through a 14″ x 24″ louvered vent in each gable: 360.3 sq in of net free area in all, against a common floor area / 150 rule of thumb of 307 sq in.

If you are weighing roofs, the 16×20 hip roof shed plan has the same footprint. In heavy snow or high wind areas, ask about loads and check your local permit office before you build.

Free 16×20 shed plan PDF vs the full plan

The free 8-page PDF shows how the plan is drawn and what the shed looks like. The full plan adds the complete material list above with every quantity, all 28 sections, the cut list, the cutting plan and the floor, roof and gable sheet maps. Before it went on sale every measurement was cross-checked with 117 checks on the framing, the roof, the sheets and shingles and the lists, and all of them pass.

Before you build a 16×20 gable shed

• Permits. At 320 sq ft and 13′ 1″ tall, this is a large shed that is over common exemptions, so most towns ask for a permit, and rules on size, height and setbacks vary by town and HOA. Call 811 before you dig, and check your local permit office before you buy lumber.
• The pad. The 6.7 cu yd of 3/4″ stone fills the pad inside a frame of pressure-treated 4x6s pinned with 36 rebar stakes.
• Skids. Use ground-contact rated pressure-treated 4x4s (UC4A or higher), set each one crown up, and raise a low skid with more gravel or treated shims, never untreated wood.
• Anchors. An empty shed on loose skids can slide in a strong gust, which is why 8 ground anchors, 4 along each outside skid, are on the list. Check your local permit office for what your area asks.
• Keep it dry. Leave 6″ or more between the siding and the soil or mulch, and check the roof, caulk and paint every spring.
• Materials. Store lumber flat and covered, since wet wood decays faster (USDA Forest Products Laboratory Wood Handbook). Check the stamp on each OSB sheet for its span rating (APA: OSB).

Ladders the plan lists

Two 10 ft step ladders reach the ridge, and a 16 ft extension ladder covers roof work from the eave, about 8′ 8″ up.

Related plans

• 4 ft longer: the 16×24 gable shed plan. 2 ft shallower and 4 ft longer: the 14×24 gable shed plan.
• 4 ft shallower: the 12×20 gable shed plan.
• Same 20 ft width under a single slope: the 14×20 lean-to shed plan.
• Choosing a base first? Read the shed foundation guide.
• Every gable shed plan in one place.