Once thought to be the ‘poor man’s timber,’ bamboo is gaining respect as a sustainable way to protect human life and property against hurricanes and earthquakes.
At the time of publication, it’s been nearly twenty-four hours since New Jersey, New York City, and Philadelphia experienced a flash flood from the remnants of Hurricane Ida. It claimed the lives of twenty-nine people, so far. Further, the images and videos are mind-boggling: water pouring into the subways and lower level apartments, streets turned into rivers in minutes, and confused rats lolling down the flooded alleyways. It’s the latest in extreme weather events that have started the Great Climate Migration. Maybe we have to leave these hurricane prone and low lying areas, or maybe we build better. Future, meet the bamboo house.
Because it’s well time for us to not only adapt, but to build to survive.
The Bamboo House in a Hurricane
Bamboo is a highly renewable resource and grows as a flexible plant that can withstand very high wind speeds – up to 173 mph winds! That’s as it grows and as a building material.
Bamboo living is the opportunity to have sustainable housing that can also survive the perils of climate change and natural disasters. The plant itself can bend all the way to ground level under the weight of high winds or even heavy snow or hail, and then straighten back up to full height when the weather passes.
Plus, according to the Harvard Business Review, “properly constructed bamboo homes surpass the toughest hurricane codes in the U.S. In 1995, bamboo homes withstood three back-to-back hurricanes in which winds maxed out at 173 mph. Recent tests show that conventionally built wood homes can’t stand up 100 mph winds.”
The Bamboo House in an Earthquake Zone
Bamboo is an ideal building material for both hurricane and earthquake zones because it has twice the compression strength of concrete and a higher strength-to-weight ratio than steel.
Interestingly, an article published in Washington’s Observer Reporter (1991) tells the remarkable story of how all twenty of the bamboo houses built for the National Bamboo Foundation survived a 7.5 magnitude earthquake in Costa Rica. Even more, the bamboo housing was located at the epicentre of the quake. All around these bamboo oases were toppled homes and hotels made from more conventional construction materials.
Bamboo Housing Makes Sustainable Living
When compared ounce for ounce, bamboo is stronger and more sustainable than wood, brick or concrete. An interesting fact from Discover magazine is that, “a straight column of bamboo with a top surface area of 10 square centimeters could support an 11,000-pound elephant.”
Growing Bamboo
Bamboo uses a rhizome-dependent system, making it very fast growing and sturdy (some would even say ‘invasive’). In fact, bamboo is ready to harvest every three years, which is three times faster than even the fastest growing tree.
The plant grows from seed to form clumps. Each clump has bamboo poles, called culms. While a clump can live for 50 to 150 years, a culm will reach maturity in about three years. Further, culms can grow 10cm per day!
Importantly, not every bamboo species is suitable for building. Many are completely hollow! Valuable species for construction include: Guadua, Dendrocalamus and Phyllostachys. These species can grow forty to fifty feet high with poles that are up to five inches in diameter.
Harvesting Bamboo
Unlike logging trees, bamboo can be harvested without degrading the soil. It can also be annually cropped for decades without replanting the clump.
Importantly, once bamboo enters the construction cycle and becomes part of a bamboo house or other eco-development, it serves as a carbon sink with a zero carbon footprint.
Finally, processing bamboo needs only 1/8 of the energy of concrete and 1/3 of that need for wood. Compared to steel, it’s remarkably more efficient to process – at 1/50th of the energy need to prepare steel for construction.
Bamboo Housing Benefits for Humans
Some of the key benefits of bamboo for structures that can withstand the challenges of climate change include:
- High Tensile Strength – its fibres run axially, giving bamboo a higher tensile strength than steel. This is a measure of the resistance of a material to breaking when under tension (such as the sustained winds of a hurricane).
- Fire Resistant – bamboo will survive temperatures up to 4000C.
- High Elasticity – bamboo is highly flexible and able to bend and return to shape. This is one of the characteristics that make it a successful candidate for housing construction in earthquake zones.
- Low Mass – a low weight makes it cheaper and easier to transport and install bamboo than wood.
There are, however, several key drawbacks that must be dealt with. Bamboo needs preserving against shrinkage and fungus. It is also a challenge for jointing during construction. Finally, bamboo is not suitable for foundations. In fact, an untreated bamboo foundation will only last about two to three years before rotting.
Roadblocks to Sustainable Housing
The COVID-19 pandemic that began in 2019 has resulted in a huge increase in the cost of building materials, largely due to disruptions in supply chains, but also inconsistent availability of qualified personnel to process, ship, and build. The price of wood, brick, and cement have contractors and customers, alike, looking for more sustainable and affordable options.
As mentioned, not every species of bamboo is appropriate for construction and those that are, primarily grow in certain parts of the world, namely subtropical regions of Asia, Africa, and Latin America. It is difficult to procure the right quality for a housing project. Further, many Western nations lack building codes that would include allowances for a bamboo house.
Is a Bamboo House Coming Soon for You?
The answer to that question depends on a lot of things: government regulations, architectural design advancements, more educational opportunities for students learning about housing and construction, pressure from environmental groups and NGOs to create safer and more sustainable human housing.
With the consequences of climate change upon us, it’s time to create better designs with more sustainable and effective materials. The bamboo house is one important step in the right direction.
