Bamboo, the builder

Nivedita Khandekar 

A tony bamboo house installed near the open lawns at the India Habitat Centre in Delhi (IHC) has been the centre of attraction for visitors since mid-December. Installed on the sidelines of the annual GRIHA Summit, this is a 240 sq feet bamboo cottage for a ‘cosy and comfortable living space’. The summit finished a long time back, but the cottage continues to be at the IHC, prompting visitors to take photos of it or click selfies in front of it. A poster displays the information about why it is there, and many people make the effort to read it.

The Energy and Resources Institute (TERI), which had installed the aptly named ‘VenuKutir’ (bamboo in Sanskrit is Venu), said the idea was to highlight the fact that the use of steel, concrete, aluminium and glass in construction ends up negatively impacting the atmosphere through the release of greenhouse gases (GHGs) during its production as well as construction. In contrast, studies have established that bamboo emits oxygen during its production and selected species of Indian bamboo sequesters up to 200 MT of carbon dioxide per hectare per year. Hence, bamboo is one of the most sustainable and environment-friendly materials to build a structure with a negative carbon impact and can become the go-to material for sustainability. Indeed, bamboo can be used to build durable and contemporary structures that appeal to the aesthetic senses of the millennials and old generation alike.

Almost all states of North-East India have a variety of bamboo houses, with unique designs for each of the ethnic groups. In recent years, an increasing number of resorts have been using bamboo but there is yet no widespread use of bamboo in construction business overall.

Traditionally, across India, timber and bamboo have been the most favoured building materials. But thanks to skewed policies such as the one that put bamboo under ‘tree’ category and blind aping of the western designs, the use of cement/RCC in buildings has gone up exponentially. Then, a major policy change happened in December 2017 when the Centre pulled bamboo out from the ‘tree’ category and put it back in the ‘grass’ category. This eased the restrictions on its commercial growing and cutting. The real impact, though, will be seen on ground once the business eco-system involving bamboo is stabilised.

Back to bamboo and timber housing

Once, each of the regions had a unique architecture to showcase, entirely based on locally available resources. A Himachali house would have a slate stone roof and timber below it for support, Konkan coastal area house a sloping red-tiled (kavelu) roof, a typical Madhya Pradesh rural area house a mud-floor/mud-wall house polished with cow-dung paste, or a traditional house in Arunachal Pradesh have bamboo as a major player with wooden logs for stilts.

Travel to any city across India, they all have started to look the same — hideous RCC buildings, similar high-rises with no or very less aesthetics, stone tiles adorning the floors and at times walls, and, in recent decades, the glass façades. The virus is spreading to the rural areas, too, as living in a pucca makan (a cement concrete house) is aspirational. The latest government announcement of ensuring a pakka makan to all also points towards brick and cement buildings.

Policymakers and common people do not realise that most of the building materials used today cause environmental damage (loss of forests due to mining included). There is transportation cost as it needs to be ferried across long distances. “Any of the materials we use — steel, cement, aluminium — leaves a trail of environmental destruction. How long can we continue inflicting environmental damage? There is soon going to be a crisis for the whole of the building industry, especially in view of the looming climate change,” says Prof KT Ravindran, architect, town planner and former head of Delhi Urban Arts Commission (DUAC).

Ravindran himself has been extensively using timber in various forms in his projects. And no, he does not advocate cutting primary forest for timber. Instead, there is ample scope for using secondary timber. It grows rapidly and there are a variety of options available. He also advocates the use of bamboo that grows rampantly all over.

Bamboo is a highly underutilised produce. It regenerates itself and for commercial plantation, too, it grows very fast. It can be a gamechanger if wisely deployed in building both high-end houses using chemically processed bamboos and low-cost affordable houses. It will not just help bamboo growers multiply incomes but also prevent damage to Mother Earth.

Strong and sturdy 

Delhi-headquartered non-profit Indian National Trust for Arts and Cultural Heritage (INTACH) has initiated a project documenting the vernacular building forms, local construction materials and techniques. As state-wise inventory piles up, most common traditional materials surface as timber and bamboo.  “It is only now that Indian construction companies are waking up to replacing many things with bamboo. There are bamboo boards, flooring, plyboards, furniture, etc.  Everything made of bamboo is available in the market for quite some time, but in the absence of any incentives, production never really scaled up. There needs to be a demand so that with volumes, prices can come down too,” observes Sandeep Theng of the Indian Federation of Green Energy (IFGE).

Sceptics question the use of timber and bamboo for high-rises, saying bamboo or timber can be good only for single or double-storey houses. How can it replace the booming high-rise building business? “People are unaware that bamboo’s tensile strength is far more than steel. It can very well be used in high-rise buildings,” Theng says.

Ravindran points out, “It has also something to do with the quantum of buildings. High rises are unsustainable. They are expensive not only from a monetary perspective but also from an environmental perspective.”

To begin with, timber and bamboo buildings can be used to construct public utility buildings and government departments in cities. Bus stops, car sheds, bill payment kiosks, educational institutions, community buildings and many other buildings that are not high rises can easily be built using timber and bamboo.

 “There should be a policy of incentivizing the use of bamboo in any type of building construction and by every ministry,” Theng suggests.

A tool to fight climate change

The International Bamboo and Rattan Organisation (INBAR) lists benefits of bamboo for a wide range of livelihood applications, especially with other forest resources becoming increasingly strained in the times of worrying climate change. Bamboo itself and many durable products made from bamboo can be potentially carbon-negative as they act as locked-in carbon sinks in themselves.

With high unemployment rates and ongoing agrarian crisis, bamboo helps farmers adapt to adverse circumstances due to the changing climate. Bamboo and its products can provide year-round livelihood.

Published in ‘Scientific Reports’, a recent study by researchers at Cambridge University (UK) and University of Natural Resources and Life Sciences in Vienna (Austria) that examined bamboo’s thermal conductivity showed that “the amount of heating and cooling required in buildings is fundamentally related to the properties of the material they are made from, particularly how much heat the materials used can conduct and store.”

Bamboo use can dramatically reduce emissions compared to traditional building materials and help mitigate the human impact on climate change, Climate News Network reported quoting Darshil Shah of the Department of Architecture at Cambridge, who led the study. “People may worry about the fire safety of bamboo buildings. To address this properly, we have to understand the thermal properties of the building material. Through our work, we can see that heat travels along the structure-supporting thick cell wall fibres in bamboo. So if exposed to heat, the bamboo might soften more quickly in the direction of those fibres. This helps us work out how to reinforce the building appropriately.”

A while back, a statement from the Potsdam Institute for Climate Impact Research advocated that buildings can become a global CO2 sink if made out of wood instead of cement and steel. A material revolution replacing cement and steel in urban construction by wood can have double benefits for climate stabilisation, it says. First, it can avoid greenhouse gas emissions from cement and steel production. Second, it can turn buildings into a carbon sink as they store the CO2 taken up from the air by trees that are harvested and used as engineered timber. “However, while the required amount of timber harvest is available in theory, such an upscaling would clearly need most careful, sustainable forest management and governance,” experts warned. That is where the government policies in propagating commercial secondary timber and wide bamboo plantations can play a major role.