Nest boxes to buy: a shortlist checked against the BTO
The BTO’s buying rules (hole size, at least 15 mm walls, 130 square centimetres of floor, no perch, no metal or ceramic) and four Amazon UK nest boxes checked against them.
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A nest box is the one bird product where the details really do decide whether it gets used. The British Trust for Ornithology publishes a short list of what to look for when buying one. This page puts that list first, and then checks four boxes listed on Amazon UK against it. The full guide to hole sizes, height and timing is nest boxes: hole sizes, height and when to put one up.
The sources, opened on 14 November 2026, are the BTO’s buying a nest box and make a nest box pages. Product details come from Amazon UK listings opened the same day.
We haven't tested this. Figures are as the maker states them (checked 14 November 2026).
The BTO’s buying checklist
From the buying page:
- Insulating material. Wood, or a “special waterproof wood/concrete compound”. Not dense materials like metal or ceramics, where the inside can get too hot or too cold for chicks.
- Walls at least 15 mm thick for a wooden box.
- Floor at least 130 square centimetres inside (20 square inches). Birds may lay fewer eggs in a smaller box.
- No perch. The BTO says perches may give squirrels or weasels a foothold.
- Access for cleaning at the end of the season.
- Not built into a bird table. Nesting and feeding birds may come into conflict.
- Preservative only on the outside, and only if it is non-toxic and water-based. Cedar, oak or beech outlast pine.
Which hole
Two BTO pages, both opened on 14 November 2026, give the hole size slightly differently, and we report both:
| Page | What it says |
|---|---|
| Buying a nest box | 32 mm is “the ideal size for all small hole-nesting birds”; choose 28 mm “only if you want to restrict the box to Blue Tits” |
| Make a nest box | 25 mm for blue, coal and marsh tits; 28 mm for great tit and tree sparrow; 32 mm for house sparrow and nuthatch |
So a 32 mm box is the flexible choice, and a smaller hole is a deliberate restriction. The diagram on this page shows the three sizes side by side. Open-fronted boxes, for robins, are a different design; see sparrow terraces and open-fronted boxes. Starlings need larger holes, covered in starling boxes.
Embed this infographic
<a href="https://finchwold.co.uk/nest-boxes/best-nest-boxes-uk/"><img src="https://finchwold.co.uk/assets/images/nest-box-checklist.webp" alt="Infographic of the BTO nest-box checklist: wooden walls at least 15 mm thick, at least 130 square centimetres of floor, no perch, wood or woodcrete, and 25, 28 and 32 mm entrance-hole guidance."></a>
<p>Infographic: <a href="https://finchwold.co.uk/nest-boxes/best-nest-boxes-uk/">Nest boxes to buy: four checked against the BTO checklist</a> from Finchwold.</p>Four listings, checked against that
What each Amazon UK listing stated on 14 November 2026. Where the listing does not give a figure the BTO asks about, we say so rather than guess.
Jacobi Jayne Schwegler 1B Bird Nest Box, 32 mm entry hole
- Made of “woodcrete”, which the listing describes as wood shavings, concrete and clay. That fits the BTO’s “wood/concrete compound”, and the listing says it needs no preservatives.
- A 32 mm hole, which the BTO buying page calls ideal for small hole-nesting birds.
- A front panel that slides off for inspection and cleaning; a stainless-steel hanger and an aluminium nail for trees.
- Listed dimensions 18 × 17 × 26 cm (D × W × H), weight 3.6 kg, made in Germany. The listing mentions a 25-year guarantee after online registration.
- No internal floor area is stated. The listing showed “Only 1 left in stock”.
CJ Wildlife WoodStone Nest Box, Green, 32 mm (FSC)
- A WoodStone box with a 32 mm hole, as named. The listing gives material as wood and says FSC in the title.
- The listing is thin: it gives no wall thickness, floor area or description of how the box opens. Check the maker’s own information before you rely on it.
- Shown as usually dispatched within 4 to 5 days.
Wild Shack Bird House Nesting Box, 25 mm hole, for blue tits
- Larch, with a Welsh slate entrance protector that the listing says secures the hole against predators.
- A 25 mm hole, which the BTO make page lists for blue, coal and marsh tits. It will exclude great tits and sparrows.
- A hinged side that locks with a stainless-steel screw, built-in drainage and ventilation gaps, a lead ridge against water, and a keyhole cut-out for mounting. Made in the UK, as listed.
- No wall thickness or floor area is stated. Shown as in stock.
Walter Harrison’s Multi Nest Bird Box with three interchangeable entrances
- A wooden box that can be used open-fronted or with a 25 mm or 32 mm entrance plate.
- That flexibility suits someone who has not decided which birds to aim for. Swap the front before the season, not once a nest is started.
- Assembly required. The listed dimensions (7.2 × 10.5 × 6.9 cm) are clearly not the size of the box, and no wall thickness or floor area is given, so check those with the seller. Shown as in stock.
We have not tested any of these, and no figure here comes from a review. A metal hole-protection plate we also looked at is not listed, because its page offered no way to buy it on the day.
Choosing between them
If you want one box that most small hole-nesters can use, the BTO’s buying page points to 32 mm, which is the Schwegler or the WoodStone. If you specifically want blue tits, a 25 mm box such as the Wild Shack is the deliberate choice. If you are not sure, the multi-entrance box lets you change your mind before the season.
Putting it up, and leaving it alone
Siting decides more than brand. The BTO advice on height, shelter and keeping boxes away from feeders is in where to put a nest box. The nest box guide gives the BTO’s timing for putting it up. Once a nest is being built or is in use, it is protected by law; cleaning a nest box explains when you may open it. If you would like to watch the nest, the bird-box cameras guide compares a camera you fit to your own box with a box that has a camera built in.
Which hole size should I buy?
The BTO buying page says 32 mm suits all small hole-nesting birds, and 28 mm only if you want to restrict the box to blue tits. Its make page lists 25 mm for blue, coal and marsh tits.
Are woodcrete boxes better than wooden ones?
The BTO accepts both wood and a waterproof wood/concrete compound as insulating materials. It warns against metal and ceramic. It does not rank wood against woodcrete.
Should a nest box have a perch?
No. The BTO says perches are not necessary and may give squirrels or weasels a foothold.