Whatever floats your home: Amphibious housing makes landfall in India
Two architects are building homes in Kerala that rest on dry ground, but can float in a flood. ‘This could revolutionise living near water bodies,’ they say.
Can we build for a world in which climate crises are the norm?
That is the question that translational engineers Nanma Gireesh and Ben K George set out to answer, in 2019. What they have emerged with is a working template for a floating home, and a contract to help build two such houses, in association with the Kerala state government.
Kerala, with its extensive coast and backwaters, floods regularly, with more frequent and extreme weather events expected as we move past 1.5 degrees of global warming. The 2018 floods, in which 11 of the state’s 14 districts were hit following spells of extreme rain, proved to Nanma and Ben just how urgent the need was for new ways of living.
At the time, they were studying amphibious buildings as part of a Master’s degree in translational engineering, in Thiruvananthapuram. They didn’t want to settle into routine jobs, building structures that could no longer do the job that habitation was meant to do, says Nanma, now 30.
So they set up NestAbide, with a single-focus mission: to build standalone homes that could rest on dry ground, and float during a flood.
In September 2021, they unveiled their first prototype, built with their own savings.
Amphi Nest is a 100-sq-ft concrete room constructed at a cost of ₹3 lakh. It has a 9-tonne buoyant concrete foundation tethered to four guidance posts. The foundation is essentially a hollow box made of reinforced steel, embedded in concrete. The guidance posts are 20 cm in diameter, filled with concrete and reinforced-steel too.
The prototype sits on a wet dock that can be inundated to simulate a flood. When water reaches levels of 2 ft to 5 ft (depending on how the foundation is built) within the narrow moat-like space around the home, it rises, tethered to its posts. In this type of structure, the concrete of the structure, and the four embedded posts, hold it in place, in turbulent waters as well, Nanma says.
“Amphi Nest is not just a prototype but a tangible answer. It serves as an immersive experience, allowing people to feel its stability during rest conditions and during flotation, illustrating how amphibious structures can revolutionise living near water bodies,” she adds.
Around the world, amphibious housing is in use in countries ranging from Canada and the UK to Bangladesh, Vietnam and the Philippines.
“The technology is proven, but widespread adaptation is a challenge, partly because of a lack of local expertise outside the Global North,” says Ben, 29.
It was to the Global North in fact, that Nanma and Ben travelled, to study the concept further. They completed a two-month internship at Delft University of Technology in the Netherlands, in 2018. This included time spent at Maasbommel, the world’s largest settlement of floating homes, made up of 32 amphibious and 14 floating houses, inhabited since 2011.
In late-2019, they found a mentor who would prove pivotal to the mission, Elizabeth C English, founder of the non-profit Buoyant Foundation Project, at a global conference on amphibious architecture held in Warsaw. The young innovators spent six months working with her in Canada, where she is also a professor of engineering at the School of Architecture at the University of Waterloo.
They then returned to India and built the prototype, which has attracted the attention of the state government. Two amphibious homes are currently under construction, one in the Munroe islands in Kollam district and the other in Kainakary, Alappuzha.
“I feel that as a woman working in this field, I faced a gamut of challenges and scrutiny. But our efforts finally got us funding and support from the Kerala Development and Innovation Strategic Council (KDISC) in collaboration with the Government of Kerala,” Nanma says.
The two co-founders of NestAbide are now pursuing PhDs at Delft, as a next step towards addressing some of the challenges that this sector faces.
A key one is scale. Floating and amphibious homes around the world tend to be standalone structures, one to three storeys high. Scaling vertically involves incrementally high costs. It would also require building standards, regulations, and policy guidelines to be put in place, Nanma points out.
And yet, vertical scale is vital, if the concept is to be viable in densely populated regions. This is why building projects at scale is the subject of Ben’s PhD.
“Simple things like the lack of insurance for such homes can hinder the development of such alternatives, which is why regulatory frameworks are the focus of my PhD,” Nanma says.