The Bilbao Arena’s Green Lizard-Like Facade Defends Against the Spanish Sun

Large sports arenas tend to consume vast amounts of energy, which is why <a href="http://www.acxt.es/">ACXT Architects</a> gave the mammoth Bilbao Arena situated on a super-exposed hill in Spain an <a href="http://en.wikipedia.org/wiki/Passive_solar_building_design">energy-regulating facade</a>. Designed to look like different colored leaves, the "flapping" steel plates wrapped around the top of the arena can be removed to let in natural light and air, and to create views of the surrounding landscape. As a result, the wide corridors aren't air-conditioned at all, which cuts down a considerable amount of the building's overall energy requirement.

The Bilbao arena is located on an elevated piece of land that gets loads of sunlight

At over 80,000 square meters, that's a lot of building to have to cool

ACXT Architects cut down the major energy load with a bright green perforated facade

Designed to look like leaves, in both shape and color, the metal sheets can be removed to allow natural light and air to enter the corridors

The Sports Center below is lit with a massive skylight

Rainwater is harvested for irrigating the outside lawn, and waste water from the swimming pool is collected to clean the streets of Bilbao