Shed & Outbuilding Construction Checklist

Check local building codes to determine if a permit is required. Most jurisdictions require a building permit for structures over 120 sq ft, though some set the threshold at 100 or 200 sq ft. Verify property setback requirements (typically 5-10' from property lines and structures). Check HOA covenants for restrictions on size, placement, and appearance. Site the shed on well-drained, level ground away from underground utilities (call 811 before digging).

1. Contact the local building department or check online for permit requirements based on shed size

2. Verify the planned location meets all setback requirements from property lines, easements, and other structures

3. Review HOA CC&Rs for any restrictions on outbuildings (size limits, approved materials, placement)

4. Confirm the site drains well by observing after rain; no standing water should remain after 24 hours

5. Call 811 at least 3 business days before any digging to have underground utilities marked

- Building without a required permit, which can result in fines, forced removal, or issues at property sale

- Violating setback requirements, leading to a required move or teardown

- Siting on low ground where water pools, causing premature rot and foundation issues

- Ignoring utility easements that may require future access and structure removal

Choose a foundation type appropriate for the shed size and local conditions: concrete deck blocks for small sheds under 100 sq ft, a 4-6" gravel pad for mid-size sheds, a poured concrete slab for permanent structures, or a pressure-treated timber skid foundation. The foundation must be perfectly level (within 1/4" across the full span) and elevated above the surrounding grade by at least 4" to prevent water contact. Size the foundation to match the shed footprint plus 6" overhang on each side.

1. Check level across the full foundation in both directions using a 4' level or string line and line level

2. Verify the foundation is elevated at least 4" above surrounding grade to prevent water pooling against the structure

3. Confirm dimensions match the shed footprint with appropriate overhang

4. For gravel pads, verify compaction with a plate compactor and 6" minimum depth of 3/4" crushed stone

5. For concrete slabs, confirm proper thickness (4" minimum), wire mesh or rebar reinforcement, and control joints

- Foundation not level, causing doors to bind and walls to rack over time

- Insufficient elevation above grade, leading to water damage and rot at the base

- Gravel pad not properly compacted, causing settling and an uneven floor

- Skipping the foundation entirely and placing the shed directly on bare ground

Build the floor frame using pressure-treated lumber rated for ground contact (minimum 2x6 for sheds up to 8' wide, 2x8 for wider spans). Space floor joists at 16" on center for standard use, 12" OC for heavy loads (riding mowers, workshop equipment). Install 3/4" tongue-and-groove plywood or OSB subfloor, glued and screwed to joists. Secure the floor frame to the foundation with anchor bolts, straps, or concrete screws to resist wind uplift.

1. Verify all ground-contact lumber is pressure-treated and rated for the application

2. Confirm joist spacing is 16" OC or less and joists are properly crowned (crown up)

3. Check that the floor frame is square by measuring diagonals (they should be equal within 1/4")

4. Verify subfloor is 3/4" T&G plywood, with joints staggered and falling on joists

5. Confirm the floor frame is securely anchored to the foundation to resist uplift

- Using non-pressure-treated lumber for the floor frame, leading to rot within a few years

- Joist spacing too wide for the intended load, causing a bouncy or sagging floor

- Floor frame not square, making wall framing and door installation difficult

- No anchoring to foundation, allowing the shed to shift or blow off in high winds

Frame walls with 2x4 studs at 16" on center. Use a single bottom plate (pressure-treated if in contact with concrete) and a double top plate. Install headers over all door and window openings per IRC span tables: doubled 2x6 for openings up to 4', doubled 2x8 for openings up to 6', doubled 2x10 for openings up to 8'. Add jack studs and cripple studs at all openings. Raise walls plumb and brace securely before connecting to adjacent walls.

1. Verify stud spacing is 16" OC with proper layout at corners and intersections

2. Confirm headers are correctly sized for each opening span per IRC Table R602.7

3. Check that walls are plumb in both directions using a 4' level on multiple studs

4. Verify the double top plate is installed with joints offset at least 4' from joints in the plate below

5. Confirm all walls are securely nailed to the floor frame and to each other at corners

- Undersized headers over door openings, leading to sagging and doors that bind

- Walls not plumb, causing siding and trim installation problems

- Missing double top plate, reducing structural integrity

- Bottom plate not pressure-treated where it contacts concrete or pressure-treated floor frame

Install rafters or pre-built trusses sized for the span and local snow/wind loads. For small sheds (under 12' span), 2x4 rafters at 24" OC are typical; for wider spans, 2x6 rafters at 16" OC or engineered trusses. Install a ridge board (minimum 1x dimension wider than rafters) or ridge beam. Sheath with 1/2" or 7/16" OSB or plywood, install roofing felt or synthetic underlayment, then finish with asphalt shingles, metal roofing panels, or other approved roofing material. Minimum roof pitch of 3:12 for asphalt shingles, 1:12 for metal.

1. Verify rafter or truss size and spacing meet the span requirements and local load conditions

2. Confirm ridge board is properly installed and rafters are cut with correct plumb and seat cuts

3. Check that roof sheathing is properly nailed (8d nails at 6" OC at edges, 12" OC in field) with H-clips between panels

4. Verify underlayment is installed with proper overlap (4" horizontal, 6" at ends) before roofing material

5. Inspect finished roofing for proper nail placement, overlap, and flashing at edges and penetrations

- Rafters undersized for the span, causing roof sag under snow load

- Insufficient roof pitch for the chosen roofing material, leading to leaks

- Missing or improperly installed drip edge at eaves and rakes

- No underlayment beneath roofing, reducing the secondary water barrier

Install a weather-resistant barrier (house wrap or building paper) over sheathing before siding. Common shed siding options include T1-11 plywood siding (economical, structural), LP SmartSide (engineered wood, rot-resistant), vinyl siding (low maintenance), or board-and-batten. Install Z-flashing above all horizontal joints and proper trim around all openings. Paint or stain all exposed wood surfaces, including cut edges and end grain, to prevent moisture intrusion.

1. Verify house wrap or building paper is installed behind siding with proper overlap (shingle style, upper over lower)

2. Confirm siding is properly fastened per manufacturer specifications with appropriate nailing pattern

3. Check that all joints, corners, and penetrations are properly flashed and caulked

4. Verify trim is installed around all door and window openings with proper drip caps

5. Confirm all exposed wood surfaces are painted or stained, including cut edges and bottom edges of siding

- No weather barrier behind siding, allowing wind-driven rain to reach the framing

- T1-11 siding installed without sealing the bottom edges, wicking moisture and delaminating

- Missing Z-flashing at horizontal siding joints, creating direct water paths

- Skipping paint or stain on cut edges and end grain where moisture absorption is highest

Install a pre-hung door sized for the intended equipment access: minimum 4' wide single door for push mowers and wheelbarrows, 5-6' wide double doors for riding mowers and ATVs. Rough openings should be 1/2" to 3/4" wider and taller than the door frame. Install windows for natural light and ventilation, with proper flashing using the shingle method (sill flashing first, then sides, then head). Apply weatherstripping to all doors and caulk all window perimeters.

1. Verify door width accommodates the largest equipment that will be stored (measure equipment before framing)

2. Confirm doors are plumb, level, and operate smoothly without binding or dragging

3. Check window flashing installation using the shingle method with proper overlap at all corners

4. Verify weatherstripping creates a complete seal around doors with no visible gaps

5. Test all windows for smooth operation and confirm they lock securely

- Door opening too narrow for intended equipment, requiring removal and reframing

- Incorrect flashing around windows leading to water intrusion at the sill

- Door threshold not properly sealed or sloped, allowing water to enter at the base

- Missing drip cap above door and window trim, channeling water behind siding

Customize the shed interior for the intended use. Install pegboard or slat wall panels for tool storage, and build sturdy shelving from 3/4" plywood on 2x4 brackets for heavier items. If adding electrical service, it must be installed per NEC with a dedicated circuit from the main panel, GFCI-protected outlets, proper wire gauge for the run distance, and all wiring in approved conduit or cable. A workbench surface should be 34-36" high with a solid top (3/4" plywood or butcher block).

1. Verify shelving is securely anchored to wall studs (not just drywall or siding) and rated for the intended load

2. If electrical is installed, confirm it is on a dedicated circuit with GFCI protection and proper wire gauge for the distance

3. Check that all outlets are properly grounded and wiring runs are protected in approved cable or conduit

4. Verify tool storage (pegboard, hooks, racks) is anchored to framing and holds tools securely

5. Test workbench stability by applying lateral force; it should not wobble or shift

- Electrical work done without permit or not to code, creating fire and shock hazards

- Shelving overloaded or not anchored to studs, pulling away from walls

- No ventilation in a sealed shed, leading to condensation and mildew on stored items

- Running an extension cord from the house instead of installing proper permanent wiring