House Wren nest box
Published dimensions, a cut list for 1×10 (9 1/4 in.), and the placement rules that decide whether the brood survives. The entrance is 1–1 1/4 in. — cut it to the smaller figure if the range gives you a choice, because a hole bored oversize cannot be made smaller and lets European Starlings in.
House Wren
- Entrance hole 1–1 1/4 in.25–32 mm
- Hole above floor 4–6 in.102–152 mm
- Floor 4 × 4 in.102 × 102 mm
- Cavity depth 6–8 in.152–203 mm
- Mounting height 6–10 ft1.8–3 m
Habitat and placement: Brushy yards, hedgerows, and garden edges — House Wrens are the least fussy cavity nester in the book and will use a box hung from a porch eave.
Spacing between boxes: About 100 ft, though wrens crowd tighter than most species tolerate.
Predator guard: Baffle if pole-mounted. Cats are the main risk in yard settings.
When to install: April into June — House Wrens arrive later than bluebirds and chickadees, and a box put up in May is still in time.
Notes: A 1 in. hole excludes House Sparrows entirely. Expect the male to stuff several boxes with sticks as dummy nests; only one gets a lining. Do not site wren boxes next to bluebird boxes — wrens puncture neighbors' eggs.
Dimensions from: sialis.org spec compilation
No perch. Ever. A perch gives predators and House Sparrows a grip — cavity nesters do not need one.
Cut list
Every board you need, sized so the assembled box matches the published interior above. Pick your stock — the list updates.
1×10 (9 1/4 in.) · about 6 linear feet including waste
| Qty | Piece | Size | Notes |
|---|---|---|---|
| 1 | Floor | 4 × 4 in. | Trim about 1/4 in. off each corner for drainage. |
| 2 | Side | 4 × 10 1/4 in. | Bevel the top edge: 8 3/4 in. at the front rising to 10 1/4 in. at the back. |
| 1 | Back | 5 1/2 × 18 1/4 in. | Runs 4 in. above and 4 in. below the box for mounting screws. |
| 1 | Front | 5 1/2 × 8 3/4 in. | Bore a 1 in. hole, centred side to side, with its centre 6 3/4 in. up from the bottom edge. |
| 1 | Roof | 8 1/2 × 7 1/2 in. | Overhangs 3 in. at the front and 1 in. each side; butts against the back board. |
Before you cut
- Untreated wood, 3/4 in. thick. Cedar, cypress, or pine. Never pressure-treated, and never paint or stain the interior.
- Score the inside face below the entrance so nestlings can climb out. Smooth plywood traps them.
- Drainage and ventilation. Trim the floor corners; leave gaps or drill holes near the top.
- Make one side or the front open so you can monitor and clean between broods.
- Baffle on a smooth metal pole. This matters more than height, orientation, or anything else on this page.
When and where to put up a nest box — timing by region, habitat matching, orientation, and predator guards that actually work.
Other species
- Tree Swallow 1 3/8–1 1/2 in.
- White-breasted Nuthatch 1 1/4–1 3/8 in.
- Tufted Titmouse 1 1/4–1 1/2 in.