From environmental certifications to water and energy efficiency, we take a look at structures that were built with sustainability as a priority

The Sydney Opera House obviously needs no introduction. The famous multi-venue performing arts centre on the banks of the Sydney Harbour is one of the world's most famous and distinctive buildings in 20th-century architecture. But you might not have known about its numerous sustainability initiatives.

Currently, the Sydney Opera House has committed to the United Nations Sustainable Development Goals, which provide a roadmap to address the world’s most pressing challenges by 2030, including climate change, inequality and education.

The building has had a number of sustainable wins, including its recent Carbon Neutral certification, thanks in part to an implementation of a new waste management program, efficiencies in water use and a more than nine percent reduction in energy usage.

As he was designing the Opera House, architect Jørn Utzon kept the environment top of mind, from the building’s pioneering seawater cooling system (using seawater to efficiently cool the building), self-cleaning tiles (rainwater washes them off) and green cleaning methods (an age-old technique of using olive oil to polish brass).Sydney Opera House and bridgeSydney Opera HouseIn 2014, the Opera House replaced the light bulbs in the concert hall with custom-made LEDs, reducing energy consumption by 75 percent. In 2016, a new waste-management program was introduced, and the Opera House expanded its recycling of papers and plastics to include mobile phones, fluorescent tubes, toner cartridges and batteries.

In 2017, food waste (from staff and performers in the green room, concerts, visiting artists, etc.) was moved to Earth Power, an organics facility that converts it into energy.

Most recently, staff from across the Opera House and Energy Australia travelled to Mount Carmel in Campbelltown this September to plant numerous plant species in collaboration with Greenfleet. Over their lifetime, these trees will help absorb and store carbon, regenerate land, and eventually provide wildlife habitats essential for native species. So far, 20 staff of Sydney Opera House have planted 300 native species of trees.