For Miss Swapna Haresh Teckwani's students, learning takes place not only in the classroom, but also in the school's nursery.

After discussing biodiversity and sustainability with her Secondary 4 class during a lesson on plants on Thursday last week, the subject head of science and research led the students to the first-floor nursery.

First, they inspected the bok choy they had grown, which will be harvested later and passed to canteen vendors to be used in the dishes they sell. Next, Miss Swapna pointed out the various species of plants to her students at the greenhouse, a collaboration between Commonwealth Secondary School and the National Parks Board.

The school took about three years, from 2014 to 2016, to create eco habitats on its campus, such as a rainforest and a wetland, in a pioneering effort to educate students on sustainable living. It is one of the schools piloting sustainability concepts. The pilot begins next month and will run until 2023.

Principal Ng Boon Kiat said: "Our teachers are working with the Ministry of Education to co-create some of the curriculum and the campus for our students. We hope that with the improved curriculum and practices, we are able to transfer some of them to other schools."

Teachers at Commonwealth Secondary are incorporating sustainability concepts into the geography, sciences and language curricula.

Secondary 4 student Nur Aleesha Adam, 15, said the sustainability-themed talks during their science, technology, engineering and mathematics elective lessons spark an interest in the students. "I watch documentaries at home now about how the world works and share it with my parents," she added.

This sustainability drive, especially eliminating the use of single-use plastics, has also helped the students to develop good habits.

Fikri Hakim Shahrin, 14, who is in Secondary 3, said: "I have become more aware of the impact of climate change and global warming from geography lessons, and would want to do my part to prevent that from happening by recycling newspapers and plastic bottles, and bringing my own bag to the supermarket."

The school is also working towards reducing the carbon footprint of its infrastructure. Currently, two-thirds of the electricity it uses is generated using solar panels installed on the rooftops.

Mr Ng said the school will discuss other things with the Ministry of Education soon, including using energy-efficient LED lights and redesigning some classrooms to improve ventilation and cut down on the use of air-conditioning.