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Before you start
  • Read all steps and select mounting supplies before cutting.
  • Use 3/4 x 11 1/4 in cedar and 5/8 in exterior plywood. Check the cedar width before buying.
  • Build this box for an interior cross-beam installation. Select the mounting fasteners, surface hinges and short hinge screws before assembly; dry-fit the lid hardware.
Plan details

Standard

A broad plywood and cedar box with a 6 x 7 in entrance, twenty drain holes and a hinged roof lid.

A broad plywood and cedar box with a 6 x 7 in entrance, twenty drain holes and a hinged roof lid. Follow the illustrated assembly steps and dimensioned drawings. Matching downloads include editable CAD, exchange models, shopping and cut lists, and a Blender scene.

Open model.FCStd in FreeCAD. Boxes, profiles and boolean cut history remain editable.

Dimensions are stored in millimeters; 25.4 mm equals one inch.

For an access panel, edit Access hinge OpenAngle from 0 to 90 degrees. Recompute before measuring or exporting.

Reopen model.step in a CAD application for the closed assembly. Source files and drawings remain outside the download package.

Dimensions and opening sizes
Body widthFinished dimensions of this configuration.
36 in
Outside depthFinished dimensions of this configuration.
12 1/2 in
Closed total heightFinished dimensions of this configuration.
16 3/8 in
Entrance widthFinished dimensions of this configuration.
6 in
Entrance heightFinished dimensions of this configuration.
7 in
Lid blank widthFinished dimensions of this configuration.
15 in
Shopping list

Shop this list at Home Depot. Choose your store there to confirm prices and stock. Links open in a new tab.

BuyMaterialStock sizeHome Depot
1 sheetExterior plywood4 x 8 ft x 5/8 in
Find matching material Match the specifications in the quantity notes.
1 boardUntreated cedar1x12 x 6 ft; actual 3/4 x 11 1/4 in
Find matching material Match the specifications in the quantity notes.
1 box of 50Exterior wood screws1 5/8 in, corrosion resistant
1⅝-in exterior screws · 50-count box Buy 1 box$5.71 / boxChecked 2026-09-26 · US online listing; local price varies
2Galvanized exterior hingesSurface mount; suitable for 5/8 in plywood
2-in stainless hinges · 2-pack Buy 1 pack · 2 per pack$5.47 / packChecked 2026-09-26 · US online listing; local price varies
1 rollGalvanized soft tie wire16 gauge x 10 ft
16-gauge galvanized wire · 25-ft roll Buy 1 roll$2.97 / rollChecked 2026-09-26 · US online listing; local price varies

Priced materials subtotal

$15.72 USD

Estimated

USD, before tax, delivery, tools and labor. Retail prices checked September 26, 2026; local price and availability may differ. Includes whole boards and retail packages. Required items without a verified equivalent price are excluded and listed separately.

Still to price: Exterior plywood, 4 x 8 ft x 5/8 in; Untreated cedar, 1x12 x 6 ft; actual 3/4 x 11 1/4 in. This subtotal does not cover the complete project.

Quantity notes

Full stock units with cutting allowance; retain offcuts for fitting. Hardware counts include an assembly allowance.

  • Exterior plywood, 4 x 8 ft x 5/8 in: Two 36 x 15 3/4 panels and one 37 x 12 1/2 roof blank fit across the 48 in width with kerfs.
  • Untreated cedar, 1x12 x 6 ft; actual 3/4 x 11 1/4 in: 36 + 15 + 15 in cuts plus 3/8 in total kerf = 66 3/8 in.
  • Exterior wood screws, 1 5/8 in, corrosion resistant: 35 assembly screws, plus hinge-specific short screws and two latch screws.
  • Galvanized exterior hinges, Surface mount; suitable for 5/8 in plywood: Select screws short enough to avoid projecting into the box. Axis at top of right lid seam.
  • Galvanized soft tie wire, 16 gauge x 10 ft: Short doubled tie at two screw eyes or headed screws secures the lid.

Required installation supplies

  • Select mounting screws, bolts or anchors for the sound support and actual box weight.
  • Select pilot drill diameters for the chosen screws. Keep screw tips within the wood.
Tools & equipment
  • Saw suitable for straight cuts and shaped cutouts
  • Drill and bits, screwdriver
  • Square, tape measure, clamps and abrasive paper

BEFORE YOU BUILD

Use this work at your own risk

These files have not been checked for accuracy, safety, structural adequacy, or building-code compliance. They may contain serious errors and are not construction-ready. Obtain independent qualified design and review before building.

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Buildings and building projects are complex, and many things can go wrong. You are responsible for checking dimensions and site conditions, choosing suitable materials and methods, obtaining permits, following codes and manufacturer instructions, and getting qualified professional help when needed. To the fullest extent permitted by law, DIYPlans.org disclaims liability for damages resulting from use of this work. Read the FAQ about your responsibilities.

Instructions

Download

Step 1 Lay out the stock

  • Mark the plywood front and back at 36 x 15 3/4 in each. Mark a 37 x 12 1/2 in roof blank.
  • Allow 1/8 in between cuts.
  • Cut the 37 in roof blank into a 5 in fixed strip, a 15 in lid blank, and a 16 in fixed panel. The extra inch allows three 1/8 in saw cuts and trimming.
  • Crosscut the cedar floor at 36 in and two sides at 15 in.

Check: All eight wooden parts are marked and cut with allowance for the roof lid clearances.

Step 2 Cut the entrance and drainage

  • Mark a 6 in wide x 7 in high rectangle with its left edge and bottom 2 in from the front left and bottom.
  • Drill a starter hole inside the waste, then cut out the entrance.
  • Drill twenty 1/2 in holes through the floor. Use two rows 3 and 8 1/4 in from the front edge; locate ten holes equally from 2 to 34 in along each row.
  • Sand the entrance and drain-hole edges smooth. Keep the interior unfinished.

Check: The entrance measures 6 x 7 in, has smooth edges, and all twenty floor drain holes are open.

Step 3 Join the floor and end sides

  • Stand each 15 in side on the floor with its outer face flush with a 36 in floor end. The side depth is 11 1/4 in.
  • Predrill and drive three 1 5/8 in screws up through the floor into each side, spaced across its depth.
  • Check both sides stand square. The wall tops should be 15 3/4 in above the floor underside.

Check: Both sides stand square on the floor and their tops are 15 3/4 in above the floor underside.

Step 4 Attach the front and back

  • Fit the 36 x 15 3/4 in front and back over the floor and side edges, keeping their bottoms flush with the floor underside.
  • Drive four screws into the floor edge and four into each side edge for each panel. Stagger intersecting screws at corners.
  • Check the outside depth is 12 1/2 in, and the entrance is on the front left.

Check: The outside depth is 12 1/2 in, the entrance is at the front left, and the panels are square.

Step 5 Secure the fixed roof panels

  • Place the 5 in strip over the left end and the 16 in panel over the right end. Keep their outside edges flush with the box ends.
  • Fix the left strip with two screws and the right panel with three screws into wall edges. Predrill and keep the center 15 in lid opening clear.
  • Trim the lid to 14 7/8 in wide and dry-fit it between the fixed panels, with 1/16 in clearance on both sides.

Check: The fixed roof panels are secure and the fitted lid has 1/16 in clearance at each side.

Step 6 Hang and test the roof lid

Play animationStop animationCleaning access panel opening and closing.
Closed position before opening the cleaning panel.
  • Attach two surface hinges along the lid right edge, about 2 1/2 in from the front and rear. Position the hinge pin at the roof top surface over the seam.
  • Use the selected short hinge screws without protruding tips. Lift the lid to 90 degrees and check the opening motion shown.
  • Fit two latch screws beside the left seam and tie them with doubled wire. Keep sharp wire ends outside and turn them inward.

Check: The lid opens through 90 degrees without binding, closes securely, and has no inward-projecting screws or wire.

Step 7 Install on a sound cross-beam

  • Select a sound interior cross-beam that supports the floor and leaves the entrance facing into the building. Arrange safe access and assistance for installation.
  • Choose mounting fasteners for the beam and fix through the floor outside the drain-hole rows. The box and beam connection must resist sliding, tipping and uplift.
  • Check the lid remains accessible, the wire latch is closed, and no screw tips protrude into the chamber. Leave the interior bare and follow local wildlife guidance for monitoring an occupied box.

Check: The beam connection prevents sliding, tipping and uplift, and the closed lid remains accessible.

Sources

Functional dimensions informed by the cited Washington Department of Fish and Wildlife woodworking sheet. CAD, instructions, schedules and illustrations authored for DIY Plans.

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