The story of kath kuni

Despite everything, Naggar is still beautiful. For now.

Located more or less in the middle of Kullu Valley, Naggar is an old, regionally important village in Himachal Pradesh. Once the capital of the Kullu kings, Naggar’s ancient stone temples and exquisite kath kuni (traditional Himachali wood and stone) houses are set against an emerald forest topped by rugged, snow-capped peaks. Interrupting this idyllic scene, a line of multi-storey hotels jostles for space along the village’s arterial road. Everywhere, steel rods stick out of flat-roofed houses – promises for the future. Conspicuous in this rapidly transforming, increasingly incongruous rural fabric, Naggar’s older structures are besieged, beleaguered bastions of beauty in a place that is losing it fast.

Bhrigu Acharya grew up in one such structure – one of the oldest kath kuni houses in Naggar – no less than 500-years-old according to local legend. Acharya House, as he calls it today, is imbued with personal and community history; a carved wooden mandapa used for winter weddings once held pride of place on the first floor. The Acharya family went through difficult times, however, and the house was past its glory by the time Acharya was born. As he grew up, it slipped deeper and deeper into disrepair. The day the roof leaked rainwater, Acharya realised his childhood home was no longer habitable. Desperate for a safe place for his family, he took a loan from a friend and built a concrete house right next to his ancestral one.

That is where he lives today.

For decades countless Himachali families like Acharya’s have given up on their kath kuni homes. Most have built concrete houses next to their dilapidated wood and stone ones. Others dismantled their ancestral houses outright and used wood and stone to build, furnish, and heat their new concrete dwellings. The traditional architecture of Himachal, kath kuni is built using two hyperlocal materials – wood and stone. Widespread availability and widespread knowledge of how to build with these materials meant that for a long time, kath kuni construction was extremely economical. It is difficult, if not impossible, to identify the moment when this began to change, but by the time Acharya built his concrete house in 2010, kath kuni had already been prohibitively expensive for decades. According to rough estimates, building a kath kuni house today costs three times as much as building the same house in reinforced cement concrete (RCC). It also takes twice as long.

In a place where they were very much the primary means of shelter, how did kath kuni houses go from being remarkably affordable to remarkably expensive?

Colonial rule and the transformation of Himachal’s forests 

Wood is a vital resource in the mountains. In winters, it is used to feed the tandoors that heat Himachali homes. It is also a precious construction and maintenance material for people living in kath kuni or part-kath-kuni houses. While wood can be purchased at government depots by anyone with the money, harvesting it directly from forests is strictly illegal. Forests, and consequently, wood, are stringently protected resources in Himachal Pradesh. Though forest rights entitle locals to one tree every ten years, for any further requirement, they must follow a lengthy, tedious application process which leads more often to rejection than to success. For most of the state’s citizens, however, the forest remains the most accessible and affordable source of timber. Consequently, forest protection and access are fraught issues. In areas where the logging mafia has a foothold, contention over the forest can turn deadly.

In a state where nearly 28 percent of land is under forest cover (which, according to reports, is growing), why is there such a pressing sense of paucity when it comes to forest resources?

Locals claim that even though domestic consumption of wood is part of Himachal’s culture, commercial timber logging was unknown to the state before British rule. In their work This Fissured Land: An Ecological History of India, Madhav Gadgil and Ramachandra Guha note that the use of the forest and its many resources (fuel, medicinal herbs, nuts, fruits, honey, meat, and fodder, to name a few) was a complex affair in precolonial India, managed by local communities and village committees and regulated, for instance, through customary rights. In Himachal, a small population and multiple checks and balances at the local level meant that there was more than enough wood (and other resources) in the forests for everyone.

As Gadgil and Guha show, all of this changed with British rule.

As with so much else, the colonial government saw India’s vast forests as a commercial resource. It annexed large tracts and set up the Forest Department to manage these forests, suddenly a property of the colonial state. India’s forests were now to serve the empire’s insatiable demand for timber – to build ships for the Royal Navy, for instance, and to lay the vast network of railway tracks that forms the fulcrum of the Indian Railways today.

As kath kuni architecture and its practitioners fade away, so does a deep knowledge of the mountains and how to live in them.

From the 1860s onwards, the forest department began leasing land in the erstwhile princely states of present-day Himachal. Their purpose was maximising the extraction of deodar wood for railway sleepers. In his A Forest History of India, Richard P Tucker notes that: “Throughout the nineteenth century the new Forest Department concentrated on cutting in the deodar forests, providing more than 100,000 sleepers annually.” In Colonialism, Development, and the Environment, Pallavi Das gives even larger numbers: “In the 1870s, at the height of the railways’ demand for sleepers, the annual harvest of trees in the Punjab hills fluctuated between 29,000 and 67,000. This figure doubled in the early 1880s.” To put these numbers in context – the trees extracted were overwhelmingly deodar, and Punjab hills refer only to that part of Himachal which was under British rule. Once those forests were exhausted, the British turned to the forests of princely states such as Mandi, Chamba, and Bussahir (present-day Kinnaur and Shimla), where they extracted even higher quantities of deodar wood. The two world wars further accelerated the demand for timber. As Gadgil and Guha state, “To meet the exigencies of war, ‘fellings and sawings were pushed to the remotest corners of the Himalayas and the densest forests of the Western Ghats’.”

The colonial forest department also set about changing the very composition of Himachal’s forests. To fulfil its commercial objective, which was indeed its primary objective, the colonial forest department transformed Himachal’s mixed forests into conifer monocultures populated almost exclusively by fast-growing and commercially valuable (though environmentally disastrous) varieties such as pine. These trees took the place of much, much slower growing but locally important varieties such as deodar and environmentally vital trees such as oak (this policy of reforestation focused on fast-growing varieties such as pine was continued for decades by the present-day forest department as well).

Without the forest, there can be no kath kuni

Due to the breathtaking speed and scale at which the colonial government emptied Himachal’s forests of deodar, deodar wood, the most important material used in kath kuni architecture, became scarce. As Richard P Tucker notes, after failed attempts to regenerate the severely depleted forests of the Himalaya, colonial silviculturists learnt that “the deodar is not only slow growing but difficult to propagate.” Indeed, due to the tree’s exceedingly slow growth, the colonial forest department planned rotations or gaps of as long as 150 years between fellings in deodar forests. But large tracts of erstwhile deodar, oak, and mixed forest never recovered from decimation by commercial and colonial logging, and as a result, the wood’s scarcity only increased with time.

Hardly any new techniques or materials have been experimented with in several decades, and as those working to save kath kuni are learning, with the fading of traditional expertise, revisiting old techniques is no easy task.

The transformation of forests, forest ownership, and management affected by colonial rule went on to directly impact kath kuni construction. By the 1960s, restrictions on forest use and wood harvesting meant that kath kuni construction had effectively been banned by the government. Because there was a limit on how much forest wood one person could use, and because kath kuni houses typically crossed that limit, it was no longer legal to build them using wood from the forest. Narinder Sharma, a retired PWD officer from Naggar, reminisces about his maternal grandfather’s home, a kath kuni house built in the 1960s. Narinder ji remembers that when the forest department got wind of the construction, they trekked up to inspect the site. “My grandfather was a sharp man, he managed to convince them that because there was a larger than usual gap between alternating wooden beams in the structure, it was not a kath kuni house at all and thus, did not violate rules on how much wood he could use.” Even as kath kuni was effectively made illegal to protect Himachal’s forests, two new developments unleashed another, still ongoing wave of deforestation in Himachal – uncontrolled apple and cannabis cultivation.

The shift to ‘Pakka’ construction

At around the same time, ie, in the 1950s and 1960s, cement construction became the mainstream method of building in India – a result of both domestic demand and government impetus. In Himachal, where kath kuni construction had become ever more expensive and effectively illegal, this new construction material and method enjoyed rapid adoption. Architect Rahul Bhushan, creative director at NORTH Estate, who is working towards reviving kath kuni architecture, gives an overview; “Kath Kuni construction was still evolving during British rule, but when the Indian state was formed, the tradition faced a decline…Concrete was introduced, and the concrete and cement industry was aggressively promoted…In the process, several vernacular techniques were abandoned”. As the number of kath kuni houses began to fall, so did the number of mistries, ie, construction experts, who knew how to build and maintain them. Ses Ram ji, one of the few remaining experts in kath kuni construction in Naggar, estimates that there are around 15 kath kuni mistries in the entire panchayat as of today. Most of them are old and rarely practice their craft.

Due to the breathtaking speed and scale at which the colonial government emptied Himachal’s forests of deodar, deodar wood, the most important material used in kath kuni architecture, became scarce.

The result of this multidimensional decline is that today kath kuni is an atrophied tradition. Hardly any new techniques or materials have been experimented with in several decades, and as those working to save kath kuni are learning, with the fading of traditional expertise, revisiting old techniques is no easy task.

Of and from the mountains

So, where does this leave kath kuni architecture? According to Ses Ram ji, we are already at the end of the road for this construction technique. Somewhat unexpectedly for a practitioner, he is unsentimental about the demise of a tradition passed on from his grandfather to his father to himself. Ses Ram ji believes, and perhaps rightly so, that kath kuni’s reliance on wood as the primary construction material makes it environmentally unsustainable today and thus that, from the perspective of the environment, the end of kath kuni is no problem.

I disagree. For a multitude of often under-appreciated reasons, the decline of kath kuni is bad news.

To begin with, concrete, which has more or less replaced wood and stone as Himachal’s staple construction material, is one of the world’s worst polluters. As reports and articles note, concrete production is responsible for approximately 8 percent of global carbon dioxide emissions. It devours hills and mountains, disfiguring them with massive cavities and uprooting resident communities (herding communities dependent on these hills and mountains, for instance). It guzzles water, and as people living near any of the nine cement factories in Himachal know first-hand, it also blankets vast areas with dust, causing respiratory illness and crop failures. And finally, like plastic, cement does not disintegrate into nature at the end of its use.

There is also the inescapable fact that Himachal is a Himalayan state. The Himalaya is one of the most seismically active zones in the world and Himachal Pradesh falls under zones IV and V – the two highest-risk zones – of the Bureau of Indian Standards seismic zones map. Several districts in the state are at high risk of earthquakes, measuring 8.0 or more on the Richter scale. As we see with alarming regularity, landslides and flash floods are par for the course in this region. If this is the ground on which structures must be built, at a bare minimum, they must be resilient to the region’s challenges. Worryingly, most concrete structures in Himachal are built without the expertise of architects and structural engineers and possess no such resilience. The result is brittle buildings that collapse like cards in the face of inevitable seismic activity and climate events such as cloudbursts and flash floods.

Any building built in Himachal must also be resilient to another annual climate event – the Himalayan winter. Every year the state plunges into freezing temperatures for at least three months. During this time, concrete houses become uncomfortably cold and expensive to heat. Even beyond the winter, the difference between temperatures inside concrete and kath kuni houses is so marked that, as Ses Ram ji tells me, people who have lived in the latter find it difficult to live in the former, developing aches and pains and back issues in the first few years as their bodies adjust to their new homes.

This is because, as opposed to concrete, kath kuni houses have excellent insulation. Their double walls and mud plaster enable them to retain precious heat in the unforgiving Himalayan winter. Add to this the warmth of a lit tandoor, and temperatures inside kath kuni houses are high enough for Acharya to remember walking around inside Acharya House wearing little more than a t-shirt in the dead of winter.

As with the climate, kath kuni is also built to withstand the seismic conditions of the Himalaya. It is celebrated by architects and locals alike as an example par excellence of earthquake-resilient construction. In less dramatic movements of the earth, kath kuni fares better still. For instance, Narinder ji’s grandfather’s house survived not only an inspection from the forest department but also a landslide directly under its foundation. The house was built on a steep slope. Landslides are common in the area and during one such, the earth underneath the house slid downhill. The house, however, stayed put. Its four corners had been positioned on stable ground, and when the earth slid from underneath, the heavy wooden beams at the bottom of the house bore its weight. As a child, Narinder ji remembers poking his head under the house, peering at lights from the village downhill through the newly formed gap. Narinder ji also tells me about a cloudburst in Bhoj village a few years ago. In the flash flood that ensued, three or four kath kuni houses were washed away, but even when they were flipped over by floodwater, the wooden joinery of their walls did not open. Once the cloudburst had passed, villagers dismantled the washed-away houses and reassembled them at their original locations.

A striking combination of wood and stone, Himachal’s vernacular architecture uses sophisticated interlocking techniques to create wooden ‘frames’ that are remarkably resilient to the seismic challenges of the Himalaya. Kath kuni literally translates into ‘wooden corner’ – and this is one of its most essential features. These corners, where beams of wood are intricately interlocked together, give kath kuni structures their remarkable ductility. The interlocking system allows walls to move and adjust during earthquakes, dissipating the exceptional force generated by such seismic movements without snapping or breaking apart. Gaps between each alternate layer in the wooden frame of the structure are packed with river stones. Kath kuni structures have double walls for stability and insulation. The space between these walls is filled with stone, rubble and hay. Inside and often outside, walls are covered with a layer of mud plaster – giving these structures excellent insulation. Slate tiles are used to lay the roof, their weight pressing the entire structure downwards and adding further to its stability.

The result is a structure with a remarkably low centre of gravity, high ductility, excellent insulation, and an almost lego-like ability to be undone and remade over the years.

These properties show that, like any vernacular architectural tradition, kath kuni has evolved in response to its context. But no less important than all of its climate and terrain-responsive properties is the fact that as a product of the culture and aesthetic of the western Himalaya, kath kuni is also an integral element of what makes towns and villages in this region, towns and villages in this region. Antithetic to the flat-roofed concrete houses now copy pasted across all regions of Southasia, kath kuni does something vitally important for Himachal’s built environment – it makes it somewhere, rather than anywhere.

Finding a way forward

As kath kuni architecture and its practitioners fade away, so does a deep knowledge of the mountains and how to live in them. Standing where we are today, however, no straightforward return to kath kuni is possible. Himachal’s population has grown multifold, and lifestyles have transformed. If Himachalis were to return to kath kuni en masse, demand for wood, stone, and slate would wipe the mountains bare. Acknowledging this reality, local residents, architects, and heritage lovers are working to revive kath kuni through innovation.

Funded by the National Mission on Himalayan Studies, Resilient Himalayan Homes (RHH) is an initiative by Sanjay Chikermane at Indian Institute of Technology Roorkee to restore and revitalise the building traditions of the Himalaya. RHH is experimenting with steel to replace the wooden beams that form a kath kuni structure’s frame and purpose-cast concrete blocks to replace the wooden corners that lock these beams together. As architect Katha Mehta, a research associate involved in the project explains, “the corners and junctions and how they behave are very important elements of a kath kuni building. We’re trying to create alternatives that behave in the same way and have the same flexibility as the traditional materials.” If RHH succeeds, the amount of timber required to build this new kind of ‘kath kuni’ home will be far lesser than what is used for doors, windows, frames, and shutters.

This is one way of reinterpreting kath kuni architecture – keep the structure, the technique, the behaviour of the building, but bring in mainstream materials. By making kath kuni construction possible in cheap, easily available materials such as steel and concrete, the RHH team aims to make the excellent seismic resistance of kath kuni construction accessible once more to the laypeople of the Himalaya.

As opposed to concrete, kath kuni houses have excellent insulation. Their double walls and mud plaster enable them to retain precious heat in the unforgiving Himalayan winter.

Bhushan of NORTH Estate is keen to experiment in the opposite direction – if he can find a client open to innovation, he’d like to build kath kuni using sustainable materials like bamboo instead of wood. Bhushan explains that as a result of the decline of the tradition, there is a huge gap in technique. “Every technique is evolving all the time…If kath kuni had continued, local karigars and mistries would have continuously ‘updated’ the tradition. They would definitely have experimented with new and cheap materials like bamboo”.

A group of young architects from a completely different part of the world seem to agree. In 2018 Karolina Bäckman, Ryan McGaffney, Isabella van der Griend, and Charlotte Uiterwaal created the first project book of the Atelier for Resilient Environmental Architecture (AREA) towards fulfilment of their post-graduate studies at Technische Universiteit Delft. The AREA project book examines Kullu Valley’s most pressing problems and proposes innovative solutions. To tackle the valley’s increasingly unsustainable built environment, the team proposes the revival of kath kuni architecture through the use of new, eco-friendly materials. They suggest swapping wood with compressed bamboo, and stone with hempcrete. Bamboo is said to have a tensile strength higher than steel, and hempcrete is widely celebrated as a carbon positive, lightweight material with excellent insulation. Bamboo and hemp are both abundant in parts of Himachal, which makes them indigenous, cheap, and easily accessible raw materials. The team notes that if the necessary processing units are set up within the state, Himachal could grow its own construction materials.

Could bamboo wood and hempcrete save kath kuni?     

The bamboo wood market in India is nascent. Compressed bamboo beams, the kind that would replace wooden beams in kath kuni architecture, are rarely, if ever, produced on a commercial scale. This means that at the moment, they are expensive and difficult to source.

The material itself, however, holds some promise – bamboo beams have been used in load-bearing structures with encouraging results. As an added benefit relevant to kath kuni construction, the processing of bamboo into bamboo wood removes all sugar and starch, making the end product termite resistant. Bamboo wood does not, however, have the legendary water and rot resistance of deodar. To be used outdoors, it needs extra curing and maintenance. It is also almost double the density of most woods in the market. As a result, carpenters find it difficult to use local saw machines on bamboo wood – it must be factory made from start to finish. This is not compatible with kath kuni construction practices. Building a kath kuni house is a fluid process. Decisions about layouts and floor plans are made in situ and mistries improvise as they go. Apart from being well suited for kath kuni structures, bamboo wood would also have to be seen as well suited for the construction process. While not insurmountable, this is an obstacle nonetheless.

The situation with hempcrete is relatively better. Uttarakhand legalised hemp cultivation for industrial purposes in 2015, giving fresh impetus to hemp-based businesses in India. GoHemp Agroventures, an eco-enterprise based in the state’s Kandwal village, was one of the winners at the Global Housing Technology Challenge organised in 2019 by the Ministry of Housing and Urban Affairs. The startup’s prize-winning entry was biocrete – construction blocks made using waste from hemp fibre processing.

Gaurav Dixit, CEO at GoHemp, explains, “Hempcrete is a term coined by the market. It’s trending. When I say hempcrete, people start comparing it with concrete. But this is not accurate. The material we have developed does not contain portland cement. We use the woody core that is discarded during hemp processing, along with lime binder and a few other mineral additives. This is not a new material. It has been used in the caves of Ellora. We are actually reviving ancient Indian technology. Hemp is very versatile, and lime is a very healthy material. In hempcrete lime is in calcium hydroxide form, which absorbs CO2 from the atmosphere and converts it into calcium carbonate or limestone. So it improves indoor air quality while gaining strength over time.” GoHemp’s hempcrete blocks are in the post-prototype phase. Dixit and his team are currently building their first demo structure – a homestay in Uttarakhand. At the moment, only rough estimates are possible but Dixit calculates that with economies of scale factored in, building using hempcrete should cost only 10-15 percent more than standard structures. This difference too would soon be recovered as savings on heating and cooling costs. He estimates that by 2022 GoHemp will be able to launch its technology commercially.

To Dixit the future of biocrete appears bright – as a growable construction material, it offers remarkable renewability and, at the end of its use, decomposes back into nature. He has also been thinking about the use of hempcrete in kath kuni, or koti banal as it is called in Uttarakhand, and he’s keen to try it out when the opportunity arises.

Even if tests and prototypes establish that bamboo beams and hempcrete blocks are indeed suitable for kath kuni architecture, as architect Katha Mehta rightly points out, for these materials to become part of the solution, they will have to be integrated into formal government guidelines around construction and will have to become as cheap and as readily available as bricks, cement, and concrete. To make that happen, among other things, the state would have to fund research and testing, set up factories, and train the architects, mistries, and construction workers of today and tomorrow.

Past, present, future

If we distill the developments of the last century and a half, a striking narrative emerges; Larger social, political, and economic changes lead to the rapid exhaustion of a resource that was once abundant in a region and vital to its local architectural traditions. Fundamentally transformed ways of thinking about resources and resource use come into effect, shaping state policy and making it next to impossible to continue building using traditional materials and techniques. With the drying up of raw material supply and loss of demand, local architectural traditions begin to atrophy. They stop innovating and no longer cater to peoples’ changing needs. These traditions are then transformed from living, breathing knowledge pools solving the problems of their context to relics of the past that must be conserved and ‘museumised’.

I believe this is the story of kath kuni. And it points us in a direction very different from prevalent ideas about traditional architecture. It indicates that vernacular building traditions, in Himachal at least, have not fallen by the wayside due to society’s determined march towards betterment. Neither has any hankering by end-users for the Western or ‘modern’ been a primary force in pushing traditional materials and techniques out of favour.

On the contrary, the story of kath kuni indicates that it takes fundamental shifts in perception and policy to dislodge and disintegrate a way of building that is rooted in, and thus, spectacularly suited to its context, and to supplant in its place, a way of building that is spectacularly ill-suited in comparison. Efforts to revive kath kuni suggest that to re-access the knowledge embodied in traditional architecture, to benefit from it today, will take fundamental shifts too.

One way of reinterpreting kath kuni architecture – keep the structure, the technique, the behaviour of the building, but bring in mainstream materials. By making kath kuni construction possible in cheap, easily available materials such as steel and concrete.

The state is the only entity with the authority and resources to bring about such fundamental shifts. Regardless of its will and willingness to do so, citizen and academia-led initiatives like NORTH and RHH forge ahead. Recognising what is at stake (the very liveability of India’s built environment, no less), they are doing the difficult work of innovating and experimenting in a policy vacuum.

For Bhrigu Acharya, who dreams of rebuilding his heritage, waiting for the state to act or innovation to bear fruit is not an option. His 500-year-old ancestral home is rapidly deteriorating – if he wants to restore it, he must do so before Acharya House becomes completely unviable. Harnessing the properties of kath kuni, Acharya has found an innovative, albeit bittersweet, solution. An old kath kuni house is up for sale in a neighbouring village. The family cannot maintain it any longer and want to build a concrete house instead. Acharya has decided to buy their kath kuni house and use the wood to rebuild his own ancestral home. Along with a team of heritage and culture lovers, he has set up a fundraiser to finance the restoration*.

Acharya is optimistic about the future. He has started laying a path from his new house to his old one.

Sitting far away from all these scenes of action, I am left wondering (and perhaps, you, the reader, are too?) what if the story of kath kuni is the story of most vernacular architectural traditions in India? Or even Southasia?

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* Garima has been part of this initiative since November 2020.