The Great Tit is one of the most rewarding nest-box birds. The crucial factor is the diameter of the entrance hole — 32–34 mm admits the Great Tit, while 28 mm lets in only the Blue Tit.
| Measurement | Value | |---|---| | Entrance hole | 32–34 mm | | Internal floor dimensions | approx. 13 × 13 cm | | Height of hole above floor | 17–20 cm | | Mounting height | 2–4 m | | Aspect | entrance facing east–south-east or north |