Aviary for eagles

The new aviary for eagles at the Brno Zoo is an example of an inspiring connection between nature and technology, a robust landscape solution, and a subtle rational construction. The aviary itself is somewhat different from similar structures – although it is 30 meters wide and as tall as a five-story building, it has no internal supports, massive load-bearing frames, braces, hangers, or rods. Just a completely lapidary shape defining the space for the birds' flight among the trees.
The exhibition solution is based on the principle of immersing the visitor in the exhibition. The path runs through the elegantly shaped spaces in a terrain cut and overlooks individual exhibits – its direction below the surrounding terrain level, along with embankments, artificial rocks, and greenery, delineates views from which all distracting elements outside the composed exhibition scenery are excluded. The highlight of the visit is the entrance to the aviary, where the visitor finds themselves beneath a terrain overhang, with a view directed towards the full depth of the aviary.
In designing the aviary, the main intention was to make the upper part as wide as possible for soaring birds of prey. At the same time, the design was led by the idea of eliminating any bracing elements outside the footprint of the aviary, as this would create a number of complications in the confined space of the building site (collisions with mature trees and adjacent roadways).

The construction of the aviary is designed as a steel assembly in the shape of an inverted truncated cone. The base of the aviary has an elliptical footprint measuring 32 x 22 m, and at the top, it has a circular shape with a diameter of 30 m. The height of the aviary above the sloping terrain is a maximum of 15.5 m and a minimum of 11 m.
The structure consists of an upper compressed circular ring into which a cable membrane made of steel cables in an orthogonal grid is anchored. A nylon net is stretched over the cables. The ring is supported by sixteen steel columns placed at slanting directions at various angles.

Built-up area total: 648 m²
Built-up area of the eagle aviary: 540 m²
Enclosed space total: 8372 m³
Enclosed space of the eagle aviary: 7941 m³
Water area: 53 m²
Length of visitor path: 75 m
Weight of the steel structure: 21 t
Construction cost: 19 million CZK excluding VAT