Takashi Niwa of Vo Trong Nghia Architects talks with Design Anthology about the studio’s unconventional and ultra-natural approach to design at Business of Design Week, Hong Kong

How did you end up in Vietnam?

I’m Japanese, but I moved to Vietnam six years ago. I’m close friends with Vo Trong Nghia — founder of our office — for around twenty years now. During our student years, we did some projects in Vietnam, so I have a longstanding relationship with Vietnamese material. Also, in Japanese architecture we respect local material, like timber and tiles, then we develop buildings utilising local material. It’s like sushi or sashimi that use local ingredients for food — it’s the same for architecture.

When did you start incorporating plants into your design approach?

Actually, in the beginning of course we didn’t know its potential. Vo Trong Nghia and I studied in Japan, where planting trees on the houses is quite impossible because of their timber structures. But in Vietnam the houses are mostly concrete, so it’s easier.

We began using greenery because of the heat effect. So we started with green roofs, and then green facades, and now big trees on the buildings.

Do you have a team of horticultural experts, or are the plants that you use very low maintenance? How do you select the most ideal plants for each project?

Actually, the Vietnamese people love plants. Even if they only have a small balcony, they’ll put a bonsai or keep plants in the house. The problem is they just put it- they don’t integrate it with the space experience. In our approach, when we design buildings we think about what plants they may want to put around their houses, so when we go to see a site, we also look around to see what kind of trees would be suitable for that house. Then basically the plant will be very flexible to adapt to the situation.

Can you tell us about the creative process within your team when you’re approached with a new project?

Recently, we’ve become more interested in using big trees and how to grow trees on buildings. So first we try to make it comfortable for trees to develop, then maybe go into more details inside, looking at how to integrate green plants within the interior spaces.

Where did the inspiration come from to put trees on rooftops?

We began designing green roofs with small plants, but actually that is not so easy to maintain because small plants grow fast. Trees are easier. They need maintenance only one or two times per year, and also Vietnamese people like big trees. We use Vietnamese bonsai, which have shallow roots but can grow very big.

Are you a gardener?

I just started with my two small children. We planted vegetables on our balcony, which they’re learning about in the kindergarten.

How has being Japanese influenced your work?

Vietnamese architecture style is more decorative. They opened the country economically just ten years ago. The generation before was communist, but the new generation has a totally different background and education. So we are the oldest of the younger generation of architects in the country. Because we studied in Japan and come from the influence of Japanese architecture, we try to show the quality of the space more simply and not through decoration.

You’re working with the government to try and get new standards for greenery in the building code. How is that going?

Yes, talking to the government is one of the most important tasks for us. We want the government to look for, to push architectural ideas.

At the moment, the government is reluctant to say yes, but at the same time government officials are asking us about our concepts and want to start with their own buildings to utilise and experiment with incorporating greenery.

Would they use your architectural firm?

We don’t care so much about that. We want to share our idea with more people to spread the idea of how greenery can contribute to improving space. It’s not only an approach for making a low-energy building, it’s also deeply connected with the local climate. We utilise greenery because it’s suitable for Vietnamese spaces. I don’t like it that ‘green’ has become fashionable.