Degeneration of the atmosphere is mainly because of modern mechanical devices which have become part of our daily living.
As schoolchildren, we started reading alphabets not as mere graphical forms, but as the starting letter of a larger word. So A for Apple, B for Ball, C for Cat, D for Dog and so on it goes. Imagine, if we were to start the same again to check what impacts ecology the most, it could be a bad start.
A can be for Atmosphere, but soon we may follow it with A for Agriculture, Accommodation and Administration, all of which in the ancient times effected ecology where human actions altered the landscape to cultivate; consumed resources to construct; and created systems to govern society with capital and operational expenditures.
In modern times, A can stand for Advanced Lifestyle, but equally well for Automobile, Air travel and Air conditioners. Incidentally, these three are strongly advocated by modernity to become the aspirations of every low and middle-income family, who constitute approximately 75 to 80% of the Indian population.
These three are also among the major human actions adversely affecting nature and leading to the climate crisis. For common people, they may not appear to do so directly, but are the indirect causes due to their production, operation, energy consumption and finally waste generation upon discarding. Even the climate subject experts do not go to the depths of varied components of lifestyle, their attributes and implications on atmosphere, but gloss over them broadly saying human actions are causing the climate crisis. Then, of course, there are many people who do not fully agree with this position too.
Take automobiles, for example. Though the first car was patented in 1886, the next 20 years would not have seen more than 200 cars on the road. There was increased production, but between the World Wars, more car companies were closed than founded. The handful few from Europe, U.S. and Japan survived into the 1940s when the real mass production of cars flourished.
As such, it is less than 75 years now that people are driving cars and less than 50 years with the worldwide spread. Most poor regions have very few cars, while more than 90% of Indians still own no vehicle at all. Yet, the havoc the automobile industry has caused to millions of years of fragile nature is frightening. Hundreds of pages of data pour in today, yet none of which has reduced either car production or car sales.
In the U.S. alone, 75% of carbon monoxide and 25% of greenhouse gas emissions are caused by cars, besides many other toxic gases including ground-level ozone. Nearly three-fourths of all of U.S. gas consumption goes for cars. The resources consumed and waste generated in their production, sales, operation and finally scrapping or dumping is virtually immeasurable.
Given this, how do we analyse the impacts of our everyday living? How do we take ownership of our actions to realise we are digging our own graves? Do we need more advanced research on global issues or simple search into our personal matters?
Slabs come in many shades to protect your building from intense heat and rain.
Ask anyone if he or she prefers sunlight or shade – the answer is predictable with no failed guess! Shade is what all animals need, including humans.
Early architecture in the tropical zones of India had overarching criteria in creating shade and it was more critical than any other criteria. Incidentally, it continues to be an important consideration even today in eco-friendly designs.
Creating shade for the whole wall is among the early knowledge people picked up while designing for the climate. Initially achieved through simple ideas such as projected roofs, closely placed dense housing, deep verandahs, planting trees and such others, slowly led to windows set in thick walls, projected jharokhas and roof stone extensions. Traditionally, designs had deep roof eaves such that sunlight and rain would not penetrate deep into verandahs, porches, porticos, entrance mukha mantapas, balconies and walls facing south and west.
A formal study of buildings by experts led to a variety of options to shade specifically windows, leaving the wall open to sunlight. In normal buildings, it is common to see the horizontal chajjas or sunshades, done today mainly with RCC. Many windows also have vertical projections on both sides called fins, or it could be projections all around with a box chajja. RCC has emerged as the most prevalent material for all these, though it is not among the best options.
Among the less studied category are vertical drop slabs useful to stop both the sun and rain. They also protect our eyes from direct sunlight even when we are sitting outdoors in semi-open spaces such as balconies or entrances. Often, the upper floor common passages along the outer edges of commercial buildings would have them so the lower floors will not get direct rains. Most city homes have car porches with a room on the first floor so the clear height of the car porch may reach up to 13 feet. If the house faces south-west or direct west, evening sunlight would reach deep into the porch, heating up the car due to light and wetting it due to rains.
These vertical drops cannot be done with simple masonry, while complete concrete solutions could be costly. Traditional buildings could afford to have wooden planks in this area. Very often they are done with chicken mesh plastered on both sides, also called as Ferro-cement slabs, but they tend to crack under the strong sun over the years. Some designer buildings exhibit well placed horizontal louvres, which demand good detailing and execution.
A simple solution lies in using any stone slab, sheet metal, large clay tiles or matted material that can withstand direct sun and rain. They could be fixed with steel channel sections hung from roof slabs by inserting the slabs within the sides or grooves of the section.
If well designed and detailed to match the elevation of the building, the vertical drop slabs can be an element of attraction, rather being an ugly but unavoidable addition.
Faster construction, perks of low maintenance and aesthetics are the positives.
Is building with mud an outdated technology? Is it no more practical to do so, considering that a large number of manufactured and marketed materials have flooded our times, claiming better performance and perfection, besides variety?
This is a myth of sorts, which can be felt if we study the properties of mud, its durability and the range of aesthetic expression mud architecture achieves between different regions. With cob, adobe, soil cement block, interlocking mud blocks, rammed earth walls, pigmented walls and such others, the soil of the same place too can have multiple appearances.
Strangely, there are people who believe that natural materials like mud will have a supply problem, while factory produces like cement can be supplied forever. All manufactured materials require raw materials from some sources, mostly taken from nature itself, so they too have their limitations.
Architects, engineers and builders have built a wide range of elements using mud. To list a few, rammed earth foundation, stabilised soil cement block walls, different kinds of arches, corbelled projections, walls with inter locking mud blocks, vaults without shuttering, flat arch lintels, patterned and differently moulded blocks for parapets or compound walls, perforated walls in jaali, masonry domes without shuttering, mud block filler slab roofs, load-bearing pillars, rammed earth floor finishes, solid cob benches and fixed furniture, facia finishes, surface washes and such others have already proven themselves as doable and durable.
Should we believe that continuous innovation and constant change are the only paths towards a better future? Not really, with the carbon footprint of construction industry ever increasing. Fortunately many people today talk about the need to revive the past wisdom and blend it with modern times. But how many are willing to change the course towards natural materials is the million dollar question, especially if there are business risks associated with real estate and construction investments.
One mode of achieving it can be by value addition to the traditional mud construction. Patterned rammed earth walls have proven to be a pointer here, with increasing popularity. The mud composition needs to be the same as for other mud walls with around 15% of clay and silt each, the rest being sandy soil, but mud of different colours needs to be procured to achieve the layering of the earth. Such ideas not only let the skill-sets of the mason continue but also make them feel proud of their accomplishments.
The challenge is facing each one of us. The ecological advantages of minimising on cement, the financial advantages of faster construction, the life cycle advantages of low maintenance and the visual advantages of aesthetics of earthy construction need to be reached out to the masses.
In promoting mud architecture, each one associated with the construction sector, from the mason to the media, can play a role.
With scientifically improvised technology, mud buildings can be made to last for centuries, contrary to common belief.
It is a curious phenomenon – we all live in a planet called Earth, walk upon it, build shelters with it, and eat from it, yet we are on our way to destroy it As such, re-connecting with the Earth appears to be among the major solutions to the climate crisis. Given this, in the construction sector, we need to return to Earth, in all its terms and versions like soil, mud, terracotta, clay, silt, gravel, sand or stone.
Let us ask ourselves a simple multiple-choice question. Among all existing structures in the world, what could be the most commonly found wall material? Choice of answers – stone, mud, burnt bricks, wood. Anyone with common sense may answer it as ‘it could be mud’. Besides being the most common and most historic, mud walls have much to tell about how we lived in the past, for they sheltered the history of human civilisations. Incidentally, mud walls have a future too, in these days of climate change and ecological challenges.
The construction industry today is being blamed for one-third of GHG (Green House Gas) emissions, hence is at a crossroads. To mitigate this crisis, there is an urgent need to minimise manufactured materials and promote natural materials. The least we can do is to attempt a synthesis of traditional construction systems and modern creativity.
This is where mud architecture comes in handy. The methods of improvising traditional systems have re-validated the use of mud, to claim a pole position towards sustainable architecture.
No modern material replacing mud is yet to equal all the qualities of mud walls. It has the lowest cost in most regions; lowest embodied energy; highest insulation from heat gain; option of using mud plastering; a possibility of coating wide range of natural colours; option for bamboo or steel reinforcement; and can be used for all parts of the buildings right from foundation to roof. With scientifically improvised technology today, mud buildings can be made to last for centuries. Unfortunately, too many myths have been spread about mud, including it cracks, taking time to build, difficult to repair, monotonous and such others, as if modern construction methods are devoid of all these. This myth has come to stay, despite the fact that the way traditional mud houses lasted for centuries modern ones may not, which everyone is aware of.
So, the hesitation to build an earthy building appears to come more from fear and apprehension, than from knowledge and experience. Fortunately, mud walls are making a big return in modern architecture, though it is limited to certain regions only.
The technology of rammed earth walls has now been researched into fairly deeply and proven by various institutions such as Mrinmayee, Auroville Earth Institute, and Hunnarshala Foundation, besides many individual consultants. It is time to consider building walls with earth seriously, to save ourselves.
The design behind the ventilated cavity filler roof.
Global warming is happening much earlier than ever predicted, at which rate we may leave nothing for our future generations. While it is mandatory on all of us to reduce our consumptions, wastages, trash generation and such other measures, it is equally important to devise ways of comfortable living without depending upon energy and electricity.
Cavity roofs have been a partial solution towards passive cooling, with embedding clay pots, hollow filler tiles and such others. However, during extreme summers even the hollow clay tiles are becoming less effective.
Heat gets transferred through conduction and convection, the former through solid materials and the latter through voids and spaces. When the building terrace receives direct sun rays, it gets heated up and starts to pass the heat downwards into the room below. Even the voids inside the hollow clay filler roof would let the heat go through it, for this trapped air also gets heated with the surface heat being very high. In other words, the present day hollow clay filler roofs will let heat transfer through both the processes of conduction and convection, the void being a sealed one.
In case the trapped air inside the void which gets heated up is not sealed but move across to let cool air in, then the heat transfer would somewhat reduce. This can be achieved by inserting a small length of electrical conduit pipe between the voids of the hollow clay filler blocks, which are embedded within the RCC roof.
Once all the blocks are in place, a small length of pipes are inserted such that their ends are within the void of the filler block. It is not a continuous end-to-end pipe, which serves no purpose at all, but short connections between the voids. As the air inside the void gets heated up, it moves along the pipes to equalise the heat all over the filler block. At the edge block, this hotter air moves out of the block itself, while cooler air enters the voids from the other end.
Between the two outside edges of the slab, one would have breeze called windward direction and the other end will not have much air movement, called leeward direction. Air moves from windward to leeward directions, in the process pushing out the hot air accumulated inside all the voids of the filler roof. This would reduce the heat gain inside the room.
The ends are finished with a slight bend to block rainwater. Pipe pieces should not move so much that their end is within the tile gap which gets filled by concrete, in which case the continuous air movement will get blocked. All that the builder contractor has to oblige is let a few helpers insert the pipes, which is fairly fast. It’s a one-time investment of time and effort, to achieve passive cooling of a slightly higher order.
With earth below, the arch would be even more stable and hence can take greater load, supporting the building walls.
It is interesting to note how we tend to forget what we learn. Just leaf through an old book of medicine, construction, cooking or stitching, documenting certain ideas. Only after proving itself, that idea would have been codified, written about and became part of the book. As such we may assume the written idea is a proven idea.
Let us check how many of the ideas explained in the texts are followed now. Maybe a handful or little more, not because the rest of the ideas have failed, they have been either replaced by newer ideas or have simply been forgotten.
The art of constructing a building foundation using arches is one among such ideas – simply forgotten. We continue making arches above ground but why not below ground? With earth below, the arch would be even more stable hence can take the greater load, supporting the building walls.
There are two methods to do an arch foundation – if the full foundation would be underground, the foundation trench is dug directly with arch profiles with adequate spacing between them to build foundation piers to spring the arches. This space where arches start would need a normal footing with enough width to take on two arches. The unexcavated earth stays underneath the arch as if that’s the centring support.
If the site is lower than the road, we dig only to erect the foundation piers, taking them deep enough to reach hard soil. From the top of piers which is at the site level, we can start the arches, which should be within 5 to 8 feet span for general safety. In case of uneven sites, the rise of arches can also be varied to suit the context. Arch centring is generated by filling in mud in the required profile, where using an M.S. template ensures the curved profile is perfectly suited to take the arch action.
The curved mud profile is topped with water mud mix and manually consolidated. If the top mud layer appears very brittle, a thin cement or cement-stabilised mud mortar can be applied, ensure there is a level base layer below the arch.
Now, stone or brick arches are built just like we do in any wall and cured well. Plinth beam is placed above the arches and backfilling the earth up to plinth level completes the foundation work of the building.
Architect Rajesh Jain from R-LEEF has been reviving this forgotten technology for many years now, improving it from its textbook days. Of course, it needs an engineer’s supervision, masons with arch construction skills and contractors with inclinations to explore. If the team is not interested in exploring, the idea may fail due to a badly done job.
Imagine a small plot with a dozen RCC columns and next to it a dozen arches – both take the load. To live a green future, we need to revive older ideas
When MES School of Architecture at Kuttipuram instituted an Award for Sustainable Living, its natural choice was Mohan Chevara, Rukmini and family.
As this essay is being written and read this week, the media is full of news on the ever increasing climate crisis. A recently published IPCC (Inter-governmental Panel for Climate Change) report states that the world is warmer by 1.2 degree Celsius compared to the pre-industrial era. At this rate, we could be warmer by 1.5 degrees by 2030, much earlier than what was predicted in the last report.
The 24th CoP (Conference of Parties) is now being held at Poland with leaders from 197 nations converging at one place, hoping to converge on one decision – to resolve implementing the declarations of various past climate conventions. The former is sure, but the latter is doubtful.
This is not to connect the heads of state with climate change, but to remind all of us that we all are responsible for the crisis and the solution are within us. One such family that resolved to live with nature and practice eco-friendly living is the Chevara family near Palakkad.
When MES School of Architecture at Kuttipuram instituted an Award for Sustainable Living recently, the choice of its first recipient was Mohan Chevara, Rukmini and family.
The couple left their comfortable urban occupations in art and pharmacy education respectively and moved into a farming community which they started with a group of like-minded friends. Not believing in the commercialised school systems of today, they home-schooled their two daughters with many skill-sets, but no college degrees. Growing their own food with groundwater, their dependency on externalities was meager.
The family built a small 500 sq. ft. the house there all by themselves, except for electrician and roof carpenter, which naturally took time, but it came close to being with nature. Interwoven spliced bamboo applied over with mud mortar (wattle and daub) walls were adorned with has reliefs; frameless shutters made of split bamboo hung from top, covering the small windows with bamboo grills; bookshelves and ledges were made of bamboo; bamboo steps led to a compact mezzanine; cooking was in a tiny corner with firewood and gas as may be needed – it’s a lesson to learn from to check how less we need to live a basic life!
The house was raw, rustic but artistic. The rooms and spaces were tiny but were just about what we really need. A few material compromises and dependency on state electricity supply continues, for the project is still incomplete and health imperatives have made some demands on the final product.
Chevaras choose this lifestyle not out of compulsion of poverty, illiteracy or unemployment, but out of own choice to live with nature. They critique the modern urban living and wanted to take an alternative path to live sustainably.
Yet it was curious to note that they did not talk big and claimed to be saviors of ecology; it’s a simple way of life for them. We need more such people.
It has to be designed carefully, with proper ventilation too.
In the Indian context, ‘bright bathroom’ sounds like a contradiction! Majority of bathrooms in urban houses, with attached toilet, are ill-lit and badly ventilated.
Of course, we have quick fix solutions, without studying the root causes for the above experience. Fit a high wattage electric bulb and have an exhaust fan. Despite these two devices which consume electricity, many toilets and bathrooms are still dark during the daytime.
Actually the bathroom needs a large opening to brighten it up. There is a belief that larger the opening, lesser the privacy, which has no basis at all – a large window with translucent glass can ensure total privacy while a thin gap between the ventilator frame and the shutter can be a clear peephole. Ventilators in most buildings being rather low, most users keep them shut for the fear of privacy, incidentally blocking both air and light.
The generation before us knew the principle of ventilation that the warmer stale air moves upwards, being light in weight; hence the early toilets were provided with voids just below the roof level. During those days, with no steel and glass, these wall top openings were left with no shutters, which facilitated total movement of stale air.
The idea of continuous lintel band at 7 feet level coupled with the trouble of clearing cobwebs from this high opening made people stop the toilet ventilators at 7 feet height. With no escape, the stale air above this level comes to stay inside itself.
Most exhaust fans are operated when we are using the toilet with the doors shut, so no fresh air passes through the whole depth of the toilet. All that the exhaust fans throw out is the air immediately around them which often is fresh, so the stink continues.
Besides the general reasons, light is a prerequisite in a bathroom while fresh air is needed both for health and dry interiors. Bathrooms and toilets have been subjects of so many hilarious essays, that we may never realise how much they have in them for a serious ecological analysis too!
Among the major hurdles for air movement is the larger indoor spaces we are creating in our buildings.
Let us try this quiz – ask a hundred people if they appreciate traditional homes, and possibly the majority would say ‘yes’. Now ask if these houses get fresh air inside, and possibly the majority would say ‘no’.
Traditional homes would have few windows in the external walls and often a central court, together ensuring air circulation. Most owners cancelled courtyards, the poor built smaller houses and in some regions courts were anyway uncommon – so the stale air stayed in.
The best means of ensuring air circulation continues to be having an opening to the sky – a skylight if covered with glass, with or without a sunken courtyard. Enclosed rooms like bedrooms that cannot get a skylight, can have tall windows going up to roof level with vent at top.
In earlier times, most houses were rectangular in plan, with rooms distributed all around in geometrical shapes. Thus, one external wall of one room would get only one window. Now, let us try staggering them – push one room inside and pull one room outside. Thus, the external wall of the house would not be a rectangle with the wall line going in and out. We realise there can be many more windows in all orientations, many more corners for the room and generally much better air circulation inside.
Wind does not move in all orientations equally. Every region has its dominant directions, e.g. Kerala gets largely south-west wind, while Chennai has it from south-east. These larger trends further change directions due to trees, buildings, ground levels, seasons and such others, causing microclimatic modifications. As such, every site will have certain windward directions where pressure is high and leeward directions, where pressure is low. Wind blows from the higher to the lower pressure areas, hence windows can be located in such directions to get better indoor air movement.
Among the major hurdles for air movement is the larger indoor spaces we are creating thanks to technology. Smaller the room width, better the air circulation, but we are building large spaces necessitating ceiling fans. Even worse condition can be experienced in closely built crowded areas. The compactness nullifies all possible green cover and wind around the building, finally demanding an air conditioner. As such, both the house planning and city planning play major roles in indoor air.
Scientifically drawn-up data called wind rose diagrams are freely available today, though they may not be accurate for every site in a compact layout, but the general ideas can improve the situation largely. Roof-top fans called turbo ventilators are today popular, which need no electricity.
Past societies learnt how to live with wind, with sailors in the sea and farmers on land being the best examples. It was an animal instinct displayed by all, be it birds when they migrate or humans when they build vernacular structures. Somewhere down our modernising process, we seem to have lost this knowledge. It’s time to regain it.
We could learn from the past, since human settlements lived well without ceiling fans and air conditioners.
Open the windows – let the air come in. This line is routinely heard, meaning windows let in air. But do we really get that elusive air every time? If it were, there would not have been ceiling fans and air conditioners.
Does that mean windows do not let in air? No, it means the way we are designing the windows may not be effective. There could be something wrong in the way buildings are located or even the town planning could be flawed. If for thousands of years, human settlements lived well without ceiling fans and air conditioners, there must have been some way of living with air.
Designing for natural air is among the very basics of an eco-friendly building, so the more we capture it, the greater the efficiency. Primarily, it means ensuring cross ventilation, displacement ventilation and body-level breeze.
Cross ventilation is a very common term, suggesting air blowing through the inside of a room. Traditionally, it was achieved by windows positioned in the centre of two opposite walls, with the room itself being narrow enough for wind movement. Nowadays, two opposite walls being external is rare, hence need to shift openings to the wall corners. If diagonally placed, even larger rooms will get more indoor air than otherwise. The corner windows create an eddy, a kind of air movement, pulling in possible stale air from all over the room. Even if we get only two side walls as external walls, there can be up to four corner windows. Typically, the openings stop at lintel level, with no way for the air above 7 feet level to go out. As such, even the fan would keep throwing this warmer air down for a while! As a solution, most homes were having a small void on top of the wall to let out this stale air, now rare to see.
The void atop the wall provided displacement ventilation, an essential approach in passive cooling, now out of practice due to maintenance issues. Imagine, the top void becoming a part of the extended window which could be tall, up to the roof bottom. It could facilitate cross ventilation at lower levels and displacement ventilation at the topmost part.
The space between the lower and upper part can be fixed glass to let in light even if the curtain is pulled, with added benefits like saving on time and money by avoiding the lintel beam. Corner tall windows going up to the roof bottom allow eddy currents by bouncing air to side walls and top ceiling; light up the corners which leads to a perception of a larger room while the verticality creates an impression of spacious room.
Will the window design and location alone solve all our needs for air? No, designing for air needs many more deliberations. It’s time to explore.