# Purple martin birdhouse: Two levels, 16 compartments [View illustrated instructions](https://diyplans.org/plans/purple-martin-birdhouse-6344/variants/two-level) [Plan and other configurations](https://diyplans.org/plans/purple-martin-birdhouse-6344.md) Sixteen compartments on two removable levels, with the upper entrances rotated 90 degrees. ## License [CC BY-NC-SA 4.0 International](https://creativecommons.org/licenses/by-nc-sa/4.0/). You may share and adapt this free design for noncommercial purposes with appropriate credit, a link to the license, an indication of changes, and the same license on adaptations. See [the FAQ](https://diyplans.org/faq#license) for details and exceptions. Revision: 3 Status: published Difficulty: intermediate ## Before you start - Use plywood that measures a full 3/8 inch thick so the butt joints and half-lap partitions fit. - Rooms are 6 x 6 x 6 inches with 2-1/2-inch entrances. Current purple martin guidance favors deeper rooms and smaller entrances; confirm the housing dimensions before building. - Plan the support and a way to inspect and clean every compartment before buying mounting hardware. ## Dimensions - Floor width: 30 in. Square floor footprint. - Wall enclosure width: 19 1/2 in. Square exterior enclosure; 3/8-inch plywood. - Clear room width: 6 in. Each nesting compartment is 6 x 6 x 6 inches. - Roof overall width: 33 7/16 in. Approximate. Includes sloping eave extensions. - Height including mounting plinth: 21 3/4 in. Approximate. Excludes post and footing. - Entrance diameter: 2 1/2 in. Current purple martin guidance favors smaller entrances. ## Shopping list The two-sheet layout allows a 1/8-inch saw kerf and 1/4-inch edge trim. Solid stock includes cutting allowance. Confirm hardware sizes and quantities after dry-fitting the parts. - 2 sheets: Exterior plywood, 3/8 in actual x 48 x 96 in. Allows 1/8 in saw kerf and 1/4 in edge trim. Check both faces and measure the thickness. - 1 length: Solid wood square molding, 3/4 x 3/4 in x 8 ft. Four 13-1/2 in and two 20 in cuts total 94 in. Five 1/8 in saw kerfs and two 1/4 in end trims bring the required length to 95-1/8 in. - 1 length: Nominal 2 x 2 solid wood, Actual 1-1/2 x 1-1/2 in x 24 in. Cut four 1-1/2 in cubes for the corners of the mounting plate. - 1 piece: Corrosion-resistant wire screening, At least 8 x 8 in usable piece. Cut two 4 x 4 in patches for the gable vents. Select the mesh and attachment fasteners. - 8 sets: Exterior hook-and-eye latch sets, Select reach and screw embedment after dry fit. Allows four sets per removable joint. Check their fit and add suitable backing. ### Required installation supplies - Exterior adhesive, joint reinforcement and suitable fasteners, selected after a trial assembly. - Screen mesh and fasteners, latch backing, and an exterior roof and edge sealing system. - Post or pipe, connections and footing sized for the site, plus a lowering system or safe access for inspection and cleaning. ## Materials in the model Physical wood parts in this exact CAD model; buy stock using the purchase list. - 3/8 in exterior plywood: 25 installed pieces - 3/4 x 3/4 in solid wood cleat: 6 installed pieces - nominal 2 x 2, actual 1-1/2 square: 4 installed pieces Not quantified: - Joint fasteners, adhesive, screen attachment, latch backing and weather seals. - Post/pipe, brackets, foundation, lowering equipment and installation supplies. ## Tools and equipment - Saw with a guide for straight cuts and a 21.801-degree bevel; jigsaw for square shaft openings. - Drill with 2-1/2-inch hole saw and a backing board. - Clamps, square, tape measure, marking tools, and a chisel or router for half-lap slots. - Sanding tools and eye/hearing protection. ## Instructions ### 1. Check plywood and mounting access - Measure the plywood before laying out joints; it must be 3/8 inch thick. Confirm the 6-inch rooms and 2-1/2-inch entrances suit the intended use. Plan secure mounting and access for cleaning before buying support hardware. Check: Plywood measures 3/8 in and the mounting and cleaning-access requirements are understood. ![Two-level birdhouse with a pitched roof and round entrances.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-assembled/assembled.png?brand=1) Eight rooms per level; the upper entrance pattern turns 90 degrees. ### 2. Cut the flat panels - Follow the two-sheet cutting layout, leaving a 1/8-inch saw kerf between parts. Cut each 30-inch square floor and the roof base, then cut a centered 6-inch square air opening. Its edges are 12 inches from the panel edges. Keep the two 12-inch mounting plates solid. Check: Flat panels match the cut list; floor and roof-base air openings are centered and clear. ![Two plywood sheets with labeled part outlines and saw-cut spacing.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-cutting-layout/cutting-layout.png?brand=1) Two-sheet layout with 1/8-inch saw kerf and 1/4-inch edge trim. ### 3. Cut walls and half-lap joints - Cut W1 at 19-1/2 x 6 inches. Cut W2, P1 and P2 at 18-3/4 x 6 inches. On P1 and P2, start the two slots 6 and 12-3/8 inches from the same end. Each slot is 3/8 inch wide and 3 inches deep. Cut P1 slots from the top and P2 slots from the bottom. Test the fit on scrap first; use the wall and partition drawing to check the layout. Check: Walls and partitions dry-fit with matching 3/8-in-wide,3-in-deep half-laps. ![Wall and partition drawing with entrance locations and half-lap cuts.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-wall-layout/wall-layout.png?brand=1) Use the wall and partition drawing to locate entrances and half-lap slots. ### 4. Drill the entrances - Clamp a backing board behind every cut. W1 has three 2-1/2-inch holes centered 3-3/8, 9-3/4 and 16-1/8 inches from its left end. W2 has one hole centered 9-3/8 inches from its end. All centers are 3-1/4 inches above the bottom edge. Smooth splinters without enlarging the openings. Check: Entrance holes are smooth,2-1/2 in in diameter and positioned at the shown centers. ![Wall and partition drawing with entrance locations and half-lap cuts.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-wall-layout/wall-layout.png?brand=1) Use the wall and partition drawing to locate entrances and half-lap slots. ### 5. Assemble each level - Interlock P1 and P2 to form the center shaft and cross partitions. Butt the 18-3/4-inch side walls between the 19-1/2-inch front and back walls. Check all eight rooms and the center shaft for a clear 6 x 6-inch opening. Center the 19-1/2-inch square enclosure on its floor, leaving 5-1/4-inch porches. Use a trial assembly to select exterior adhesive or reinforcement molding and suitable fasteners. Check: Each completed level has eight clear 6×6- in rooms and an unobstructed center shaft. ![Birdhouse with its roof removed, exposing eight compartments around the central air shaft.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-open/open.png?brand=1) The removable roof provides access to the rooms for cleaning. ### 6. Make the removable roof - Cut each G blank to a 30-inch base and 6-inch rise at the midpoint. Drill the 2-1/2-inch vent centered 15 inches across and 3 inches above its base. Fit screening inside each gable before closing the roof. Place the gable outer faces 2 inches from the roof-base front and back edges. Follow the roof and mounting drawing for the cleat and roof-sheet positions. Check: Gables are positioned 2 in from roof-base ends and their vents have fitted screening. ![Drawing of the roof gable, ridge joint, cleats and ventilated mounting base.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-roof-detail/roof-detail.png?brand=1) Roof and mounting drawing. Keep the central shaft and mounting air gap open. Inch layout labels are rounded to the nearest 1/16; retain stated clearance and fit allowances. ### 7. Fit the roof sheets and cleats - Fit the four 13-1/2-inch slope cleats immediately inside the gables against the roof underside, with their upper ends 1/2 inch horizontally from the ridge. Center a 20-inch cleat along the inside bottom of each gable. Dry-fit both 30 x 18-inch roof sheets with their ridge edges beveled 21.801 degrees from square. Preserve the 18-inch outer face width. Select fasteners and an exterior sealing system suited to the plywood. Seal the ridge and exposed plywood edges. Check: Both 18- in outer-face roof sheets dry-fit on the gables with a closed 21.801-degree ridge bevel. ![Drawing of the roof gable, ridge joint, cleats and ventilated mounting base.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-roof-detail/roof-detail.png?brand=1) Roof and mounting drawing. Keep the central shaft and mounting air gap open. Inch layout labels are rounded to the nearest 1/16; retain stated clearance and fit allowances. ### 8. Build the ventilated mounting base - Laminate the two 12-inch square plates into a 3/4-inch plate. Place a 1-1/2-inch cube at each corner, flush to the plate edges. Center this assembly below the first floor, leaving a 1-1/2-inch open air gap above the plate. Keep the center shaft and side air inlets unobstructed. Have the post connection sized for the house, mounting height and site loads. Check: The laminated mounting plate and four spacer cubes leave a clear 1-1/2- in air gap. ![Drawing of the roof gable, ridge joint, cleats and ventilated mounting base.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-roof-detail/roof-detail.png?brand=1) Roof and mounting drawing. Keep the central shaft and mounting air gap open. Inch layout labels are rounded to the nearest 1/16; retain stated clearance and fit allowances. ### 9. Stack and latch the removable sections - Turn the entire upper level 90 degrees so its three-entrance sides face the lower level's one-entrance sides. Place its floor directly on the lower walls, then set the roof base on the upper walls. Align all center openings. Fit four hook-and-eye sets at each removable joint, with backing suited to the hardware. Keep the upper level and roof removable; do not glue these joints. Check: Removable sections align with the center shaft and engage their fitted latches without glue. ![Roof and birdhouse sections separated to show how they stack.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-exploded/exploded.png?brand=1) Keep these joints removable and secure them with hook-and-eye latches. ### 10. Mount the house and provide cleaning access - Complete drainage, screening, fasteners, weather sealing and secure latching before outdoor installation. Before using a 4 x 4 post or 2-1/2-inch pipe at the suggested height of 15-20 feet, have the support, connections and footing designed for the site. Provide a lowering system or safe access to inspect and clean every compartment. Check: Site-specific support, secure latches and safe access are complete before outdoor installation. ![Two-level birdhouse with a pitched roof and round entrances.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-assembled/assembled.png?brand=1) Eight rooms per level; the upper entrance pattern turns 90 degrees. ## Drawings and views ![Two-level birdhouse with a pitched roof and round entrances.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-assembled/assembled.png?brand=1) Eight rooms per level; the upper entrance pattern turns 90 degrees. ![Birdhouse with its roof removed, exposing eight compartments around the central air shaft.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-open/open.png?brand=1) The removable roof provides access to the rooms for cleaning. ![Roof and birdhouse sections separated to show how they stack.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-exploded/exploded.png?brand=1) Keep these joints removable and secure them with hook-and-eye latches. ![Two plywood sheets with labeled part outlines and saw-cut spacing.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-cutting-layout/cutting-layout.png?brand=1) Two-sheet layout with 1/8-inch saw kerf and 1/4-inch edge trim. ![Wall and partition drawing with entrance locations and half-lap cuts.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-wall-layout/wall-layout.png?brand=1) Use the wall and partition drawing to locate entrances and half-lap slots. ![Drawing of the roof gable, ridge joint, cleats and ventilated mounting base.](https://diyplans.org/media/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/image-roof-detail/roof-detail.png?brand=1) Roof and mounting drawing. Keep the central shaft and mounting air gap open. Inch layout labels are rounded to the nearest 1/16; retain stated clearance and fit allowances. ## Downloads - [Complete plan package](https://diyplans.org/downloads/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/download-package/purple-martin-birdhouse-two-levels-16-compartments-r3-package.zip): ZIP, 505135 bytes, file revision 3. CAD models and schedules for this configuration. Read instructions and dimensioned drawings on the website. SHA-256: c5a62fdcfcba7e6a98e10fc2fdc0305d9a2c52a60da9ba037cca86280ce258a6 - [FreeCAD model](https://diyplans.org/downloads/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/download-native/purple-martin-birdhouse-two-levels-16-compartments-r3-model.FCStd): FCStd, 344946 bytes, file revision 3. Inspect the rooms, roof and mounting layout in FreeCAD. SHA-256: 130b8f5a856fa1ba0dc3edb688703f983b444c9458059cd0bee86099288ccb8e - [STEP model](https://diyplans.org/downloads/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/download-step/purple-martin-birdhouse-two-levels-16-compartments-r3-model.step): STEP, 359013 bytes, file revision 3. Open the house in other CAD software. SHA-256: a0f299a1ad2f22a86da4729baee3e5206158b85686a15574a61d0cfc51420ffe - [Blender scene](https://diyplans.org/downloads/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/download-blender/purple-martin-birdhouse-two-levels-16-compartments-r3-scene.blend): BLEND, 989507 bytes, file revision 3. Editable mesh scene with simple materials. SHA-256: b0d423cefb8583ba27c3575fcc467cd4b09d55ff6af7c549291807a5ce639968 - [Cut list](https://diyplans.org/downloads/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/download-cut-list/purple-martin-birdhouse-two-levels-16-compartments-r3-cut-list.csv): CSV, 735 bytes, file revision 3. Part sizes and quantities. SHA-256: 2ab6a8b866eb225936e500e6ba044ce372d39d777534990c58cea64aa52878b9 - [Shopping list](https://diyplans.org/downloads/packages/657b6842d49ea2a89911de3db44ab7445ce39a70825e5763167e92e5812e2721/download-shopping-list/purple-martin-birdhouse-two-levels-16-compartments-r3-shopping-list.csv): CSV, 1747 bytes, file revision 3. Stock sizes, purchase quantities and cutting allowances. SHA-256: 4b970c766dec2c6fad31dc0b203c58279a51e1b6ae22a4f6c317e51abe3321c0 ## Using the CAD files - Open the .FCStd file in FreeCAD to edit the model. Import the STEP file into other CAD software. ## Sources Based on the 1969 Purple Martin Birdhouse drawing hosted by North Dakota State University. Models, drawings and instructions by DIY Plans. - [Original EX.6344 drawing](https://www.ag.ndsu.edu/aben-plans/6344.pdf) - [NDSU miscellaneous building plans catalog](https://www.ndsu.edu/agriculture/ag-hub/ag-topics/ag-buildings/building-plans/miscellaneous-building-plans) - [Texas Parks and Wildlife purple martin management guidance](https://tpwd.texas.gov/publications/pwdpubs/media/pwd_bk_w7000_0254.pdf)