To minimise bird collision risk, a building must meet the following requirements:
- At least 90% of the material in the exposed façade from ground level to 16 m (the primary bird collision zone) has a Threat Factor of 30 or less, as determined by controlled experiments by the American Bird Conservancy.
- At least 60% of material in the exposed façade above the collision zone meets the above standard.
- All glass surrounding atria, courtyards, terraces, green roofs and balconies meets the above standard.
- There are no “see through” passageways or corners.
- Outside lighting is appropriately shielded and directed to minimize attraction to night-migrating or nocturnal birds.
- Interior lighting is turned off at night when not in use. When and where lighting is necessary, minimize light spillage by covering windows or through other measures.
- Landscaping is designed without features known to increase collisions.
- Actual bird mortality is monitored and compensated for (for example, in the form of habitat preserved or created elsewhere, mortality from other sources reduced, etc.).
Source: American Bird Conservancy