Eastern Bluebird House Plans: Dimensions, Cut List and Mounting

How to read the eastern bluebird house plans sheet

The sheet above has two drawings and a cut list, all generated from the same numbers. The first drawing is the front panel seen from outside. The solid outline is the board, the black disc is the entrance hole, and the long dashed line across the lower part marks floor level inside the box. That line sits a little above the bottom edge because the floor is recessed from the bottom of the walls, which keeps water that runs down the walls from standing under the floor.

The dashed frame around the hole is the part that needs explaining. It does not show the hole’s size. It shows the band inside which the center of the hole may sit, and the figure at its left is that band’s height above the floor: 6 to 8 inches here. The reason for a band is covered in its own section below.

The second drawing is a side section. It shows the interior depth, measured from the floor up to the underside of the roof, the width of the side panel, and the wall thickness as two dashed lines outside the box. The cut list lists each part with its width, length and the board it comes from.

The inches and millimeters switch above the drawings changes every label at once, including the cut list. It converts the same figures; nothing is rounded to a different design. Without scripting, the inch figures are shown.

Sourced dimensions for an eastern bluebird box

Every number below comes from a named page. The overview of species and hole sizes sits on the birdhouse plans and placement page; this page concerns one box.

• Entrance hole: 1 1/2 inches, round. This is the figure in NestWatch’s entrance-size chart, and Oklahoma’s wildlife department gives the same “1 1/2 inches” for its bluebird box. NC State Extension also lists 1 1/2.
• Floor: 5 1/2 by 5 1/2 inches. NestWatch’s species page gives this as the box width and length. Oklahoma’s plan uses a smaller 5 by 5 floor; NC State agrees with 5 1/2. A 5 1/2 inch floor satisfies both, which is why the sheet follows NestWatch.
• Interior depth: 9 inches. NestWatch and NC State give 9; Oklahoma gives 8. The sheet uses 9.
• Mount height: 4 to 6 feet. NestWatch and NC State agree.
• Setting: grassland or open woodland, attached to a pole, per NestWatch.

The depth deserves one caveat. NestWatch labels the figure “Interior Depth” without defining it further. The sheet treats it as the distance from the floor to the underside of the roof, and the side section draws it that way.

Entrance height above the floor: what each source said

This is the one dimension on the sheet that is drawn as a range, because the sources do not agree. Oklahoma’s plan gives the entrance as 6 inches above the floor. NC State Extension’s table gives a hole height of 8 inches. NestWatch’s species page gives no entrance height for this box.

Neither source is wrong about its own box, and both fall inside the dashed frame, which runs from 6 to 8 inches. A builder who follows Oklahoma puts the hole center near the lower edge of the frame; one who follows NC State puts it near the upper edge. The sheet does not choose between them, and this page does not either. A local nest-box program, if one covers the area, is the better tiebreaker, since it has watched boxes in that region.

One limit applies at the top of the range. The hole, centered at 8 inches, must still clear the ceiling of a 9 inch interior. The sheet checks that and refuses to draw an entrance that runs into the roof.

Features every box needs

NestWatch’s page on the features of a good birdhouse applies to every species box on these sheets, bluebirds included.

• No perch. NestWatch says a perch is unnecessary for the birds and can help predators get in.
• At least four drainage holes in the floor.
• Ventilation near the top of the side walls, so warm air leaves without a draft at nest level.
• A hinged side or removable panel for cleaning and monitoring.
• A floor recessed at least 1/4 inch up from the bottom of the walls.
• Walls at least 3/4 inch thick. A board sold as 1 inch is 3/4 inch thick, so ordinary lumber qualifies.
• A roof that overhangs the front by 2 to 4 inches and the sides by 2 inches.

The diameter and number of ventilation and drainage holes are not given here. NestWatch, NC State, Oregon State and Oklahoma each state different hole sizes, and the sheet does not draw them. Only the count of drainage holes, four, is shared by the sources that give one.

Cut list and assembly order

The cut list is one layout of the box, and this section describes how it was laid out; it is not a rule from any of the sources above. The sheet assumes the common arrangement in which the side panels fit between the front and back panels. That is why the front and back are 7 inches wide, the 5 1/2 inch floor plus a 3/4 inch wall on each side, and why the sides are the full 5 1/2 inch width of a 1x6.

In that layout the sequence is short. Cut the four panels and the floor. Drill the entrance in the front, then the drainage holes in the floor and the ventilation holes near the top of the sides. Fit the floor between the sides, set 1/4 inch up from their bottom edges. Fasten the sides between the front and back. Hang one side on a pivot, or make the roof removable, to meet the cleaning requirement. The roof, cut to the overhang rule, goes on last.

The front and back are 9 1/4 inches tall: the 9 inch interior depth plus the 1/4 inch recess. Total lumber, before saw kerf, is 24 inches of 1x6 and 18 1/2 inches of 1x8. The 1x8 pieces are ripped down to 7 inches (board sizes are on the plans overview).

Placement and mount height for a bluebird box

Bluebirds nest in open country, so the box goes where the habitat is open: grassland, a field edge, a mowed lawn beside open woodland. NestWatch lists the attachment as a pole, at 4 to 6 feet. A pole also allows a predator guard, which the pole and housing guidance on the main birdhouse page covers for several species. Facing, spacing between boxes and the House Sparrow problem are likewise discussed there and are not repeated here.

How these figures were set

The entrance hole, floor, interior depth and mount height come from the Cornell Lab NestWatch eastern bluebird page and entrance-size chart, checked against Oklahoma and NC State Extension. Lumber widths come from the Southern Pine Inspection Bureau. The panel sizes and lumber lengths are arithmetic on those figures for one standard construction: sides between front and back, 3/4 inch boards, floor recessed 1/4 inch. The roof is not dimensioned. Where sources conflict, as on entrance height, the sheet shows the range both fit in rather than one value. Limits: boxes are tested in particular regions, and a local nest-box program may advise otherwise. Reviewed 2026-10-06.