Can you talk more about your focus on natural materials?

We use bamboo, timber, rammed earth, stone and more. We use trees, and not as decoration but as an essential element of architecture. Some people build a building and put trees on top. We want trees, and all-natural materials, to interact with the building. To limit water and flooding. To filter the sun. To filter sounds. To improve high-density living. On top of that we try to recycle water, use solar panels. We try to merge natural energy and natural materials.

How do you plan to change your field?

We want to use vernacular and modern design together to help solve the problems of high-density cities like Ho Chi Minh City and Hanoi . Vernacular design really harmonizes with nature. It was already there before electricity. It knew how to deal with really hot weather, for instance. Nowadays with higher populations, higher density and less land, this vernacular cannot be applied 100 percent. So we’ve started to develop a new type of architecture to harmonize with these new conditions, and with people’s modern lifestyles. I’ve tried to make architecture become a mini-park for the city. And we’ve learned from local vernacular how to use simple materials and techniques.

In our office we have air-conditioning, but we don’t use it. We have greenery all around us, irrigated through a rainwater harvesting system. A water system cools the air. But we built it for very cheap. It’s filled with beautiful, simple details.

We’re bringing this approach to a much larger scale. Every master plan we’ve done is filled with parks or gardens. We’ve also established a fund to help people throughout the country plant more trees: in schools, on roads and in the countryside. Our architecture and master plans are not enough, and we want to reintroduce the natural world as widely as possible.