ARC Studio is known for its high density urbanism work such as the pioneering Pinnacle@Duxton that redefined high-rise public housing in Singapore. How does The Tembusu build upon these ideas?

Khoo Peng Beng (PB): When we were doing Duxton, there were three things that really inspired us. One was for high-density buildings to look very porous, light and not feel like a wall. The second thing is to host a lot of greenery to bring nature closer to the residents. The third is creating architecture that facilitates the formation of community.

We were doing this quite intuitively in Duxton, but in recent years, neuroscience and social science has added to our knowledge of public spaces and community building, such as what makes a city happy and liveable. The Tembusu expresses these ideas of human-scale with its “thick skin”. The original variation of the tropical high-rise came from the International Style, which is basically enclosed by a glass wall that can be very alienating. But in the tropics, the lighting, the rain condition and the exposure are different. A lot of people want to be able to go outdoors. A building with a thick skin can host greenery and also public spaces. It’s also an environmental filter that creates a new tropical identity for the building. The Tembusu is one expression of this living façade.

Did this aim of achieving human-scale lead to the creation of a high-rise that gives “the sensation of a low-rise apartment living”? How was this achieved?

Belinda Huang (BH): Rather than a reaction to thescale, the main selling point was the community space. By bringing sky terraces up, the space feels a little more intimate because it’s only six floors. This means that three floors will have the view of a tree on the sky terrace and the upper three floors can look down on it. This also gives owners that sense of a smaller scale.

Usually, sky terraces are full floors and you have to go to the ground level to meet people. But what we’ve created are more “landed units” by designing sky terraces that come right in front of the unit. They are public areas and residents can walk in front of the units. It’s intimate yet, there is a certain distance because there is enough green between the pathway and the balcony. This is what some of the studies about creating a “happy city” talk about—a balance between private and public.

Laurence Liew (LL): With a bit of creativity, you can create a lot of variability in high-density living and humanise the design. In Duxton, we explored the sky terraces built within the floor plane. When you are in an apartment which is not on this floor, you 3 still see yourself as being in a fairly typical high-rise. But in The Tembusu, the sky terrace is basically a plane that wraps around the building. This second layer helps residents feel the green environment when they look out through the windows, even for those whose apartments are not sitting directly on the plane. In a typical condominium, you have to look down to appreciate your condo’s grounds, so you don’t feel it because it’s too far.

PB: Bringing the “ground” upwards and creating a sense of scale are very important for humans to feel safe and comfortable. As our buildings get bigger and taller, public spaces tend to feel less intimate.

Bringing greenery and public spaces into the façade of the building allows users to experience that intimacy again. The neighbourhood around The Tembusu is also primarily low-rise. By creating three stacks of low-rise buildings—one on top of the other—it helps connect the condominium to the landed properties around it.

Communal spaces feature prominently in this development. There are community herb gardens at the 18th storey, sky pods at the 6th storey and pavilions on the ground floor. A series of sky links at various levels also connects neighbours to the other blocks. Why are these important to people living in a high-rise development

BH: We just love giving opportunities for people to meet. What happens in high-rise living is that a lot of people take the lift, go up to their unit and they vanish. The sky links will encourage people to keep walking past everybody’s unit. Some of the links are also larger to serve as community spaces. This means residents don’t have to go down and up to get to another block; they just land on the sky terrace floor and can connect to the entire estate. This creates opportunities for everybody in every block to meet.

PB: This idea of connecting is like networking the buildings. Since we can create gardens that go around the buildings, would it not be nice to link them together to form one large contiguous space like a piece of fabric? We also took away some units on these floors to create double volume spaces for people to gather, play and throw parties. As the apartments are fairly compact, residents and their guests can spill out into these public spaces as an extension of their homes. Having a combination of greenery, large and small communal spaces, and linking them up, fosters movement, activity and connection. This is what we try to do to form communities.

Skyrise greenery has become part of Singapore’s built environment and this is very tightly woven within The Tembusu. How does your design push this idea of nature in a living environment further?

PB: As towers get taller and taller, people feel they are further and further away from the ground and nature. Greenery and communal life become more distant. Traditionally, houses and the low-rise apartments could be integrated with nature, but the high-rise stood on its own. With our “tower of trees” concept, we can imagine the natural environment literally flowing up to the vertical spaces. When we introduce terraces and walking paths on the upper levels, you literally can have the entire tree behaving like a little mountain. This way, we are evolving architecture back towards nature.

BH: We want to bring everybody closer to nature itself. Most of the time, this happens on the ground floor. But at The Tembusu, greenery comes up where you can view in a closer proximity from your unit. The other thing we did was to have a rain collection pond which is redistributed into a man-made river. It is proven that your health improves if you’re surrounded by nature.

PB: When you introduce greenery and plants on the building, it’s going to benefit everyone around—not just the people living there. The more skyscrapers or high-rise buildings become a contributor to the environmental health and wellness, then the greater the influence of the building. Eventually, the entire precinct will benefit from the architecture.

The construction of The Tembusu is quite a feat. The sky terraces span across five building blocks at different levels and they are supported by these streamlined steel columns. Why did you design them in this manner and how was it achieved?

PB: We always try to make things look very light and very skinny. When you want a bridge spanning across the space to look like a tiny little line but can support a lot of weight, it needs a lot of engineering and designing. One of the challenges was that our sky terraces were actually pre-fabricated and the columns were all pre-cast. This means you actually have to construct them in a very accurate manner. Otherwise, they might not fit.

LL: We were able to create this very sleek edge by controlling how the engineers designed the precast panel. We’ve got good collaborators and stakeholders, and I especially have a lot of respect for engineers. If they really want to do it, they can build anything. Our job as the leader of the team is to basically get everybody on the same page.

PB: The site is actually a very special site for the developer, Wing Tai, and we wanted to capture its origins as a garment factory. We interpreted that as lightness and fragility, but we are using concrete and metal. So how do we design such hard materials in a fashion that looks very light? That was one of our key challenges. There are also cables going up the façade like threads to carry the plants. Even the pavilion has a concrete slab that is suspended like a catenary structure, a curve form hanging freely from two points, so it feels like a piece of cloth. These are some of the more poetic or artistic aspects that we love, to draw references to some of the site’s histories—not like a literal translation, but in this case, it’s a figurative one.