Category Archives: designs
Flat clay tiles make a hourdi roof easy to maintain, and the aesthetics are stunning.
What is the most critical part of a house – foundation, wall, roof, openings or staircase? The obvious answer is the roof, hence maybe the metaphorical meanings when we say ‘roof over the head’. It is of course, less visible than the walls, hence often gets lesser attention, especially where front elevation looks are more demanding.
While walls enclose the room providing protection, it is the roof that provides the true shelter. Unlike any other element of domestic architecture, here we face multiple issues to grapple with. Immediate thought could be about the structural issues, as to how to support the roof itself. Traditional architecture worked around local materials to solve this issue, while modernity has opened up innumerable options.
People across the societies have felt the need to innovate on roofs, either because there never has been a totally satisfactory design or roofs have had the scope to play with them. While the flat and sloping roofs have dominated at large, all other options have continuously knocked at the door.
Contemporary architecture using advanced software to generate a profile, computer-controlled manufacturing of components and on-site technology to assemble them all have created some amazing roof forms across the world, with architects like Frank Gehry and late Zaha Hadid leading the pack of innovators. But do they mean in our small town contexts we need to be deprived of them? No.
The Learning Centre located at Salem proves the point. With the passion of promoter Sanjay and involvement of builder Arun, their team has managed to build a magical school building. It’s it not the just the roof which is special here, but the totality of design and building.
As such and with the concept of minimising cement and concrete, the design revolved around mud and clay.
Roofing with clay Mangalore tiles has been around for over the centuries, but it needs to be only sloping due to the interlocking grooves. By replacing them with flat clay tiles, one could create a curved profile. However, placement or direction of the clay tiles is important to ensure smooth curvature and to ensure that rainwater does not clog anywhere.
Typical computer formulae will not help in resolving the S-curved roof which adorns the school building, but only an experienced structural engineer like Ravindranath could resolve it. The structure also has domes, vaults, varied kinds of filler roofs, stone slab roof and such others. As such, the behavioural patterns of roofs need to be studied and equilibrium planned for.
Of course, special attention is called for while assembling the roof for labour safety, joint filling and waterproofing the joints. The fabrication also has to be done to precision, lest the blocks may not be seated properly.
Curved clay flat hourdi roofs have advantages other than merely the novelty. They perform better for speedier construction, reduce steel with their lighter weight, ensure different aesthetics as against RCC ceilings and are easier for maintenance.
Be it the roof, wall or the whole building, architecture should not be driven by the idea of fancy, however attractive these new designs may appear to be. All the elements of design and components of construction should together aim to provide a holistic perception and experience.
We can actually live all our life in a forest, with food, fabric and shelter taken care of, avoiding the urban claptrap. Tamandua Rain Forest Research Station in Peru tells us how.
Let us imagine we were to be living deep inside a tropical primary rain forest. There is no real local vernacular style yet, so how do we proceed to design? We need to freshly create a local architecture from the materials offered by the context. That’s what we get to see at the Tamandua Rain Forest Research Station inside the Amazon forest, next to Las Pedras River in Peru.
It could be a large raised floor with wooden planks open all around to let light and air filter in from everywhere. The height of platform and railing would discourage crawling reptiles, rodents and such others from entering. Dealing with hot humid air is simplified by high roof with total void below roof, to allow hot air to move across the roof bottom, rather than let it move downwards from the roof. Room divisions are done with low partitions, just to provide visual privacy.
How to build
There is no electricity, telephone or internet connectivity. How do we build? We need to discover ways of constructing with human skills and basic tools that are traditionally available. The jungle is replete with construction timber for structural members, veins to get rope from them and tall grass ideal for weaving for roofing purposes.
Make the roof steep to ensure faster flow of rain water and greater structural stability.
Everything from the toilet gets soaked into the soil below. If we run out of cooking gas, firewood is around aplenty, which can also provide hot water for bathing, if needed. Food without the fancy looks and urban ingredients is essential and healthy.
Essential supplies to run the Tamandua Research Station need to come from a shanty settlement an hour away by boat. The typical daily wastes too have to be taken back, not to litter the pristine nature.
The station is not for recreation, but for research and exploring nature, as such it is austere and frugal. Yet, it connotes the possibility that we can actually live so all our life, with food, fabric and shelter taken care of. If so, why have we forgotten the pleasures of simple living and the simple pleasures of living, caught up on the trap of unsustainable lifestyle?
Until a few years ago, there was no supplied electricity, but now there are a few solar photovoltaic panels that give a little quantity of power before it gets totally dark, when one relies on candles. Until a few years ago, there was no Trans Amazonian Highway connectivity, so travel took day and night across boats, road and walking.
It appears, as we move into the present and the future, we miss out on experiencing the past. Soon, we forget it and so too about designing with nature.
The architecture at Tamandua station is the real sustainable architecture. It is born out of Mother Earth and when it reaches its end, it will return to Mother Earth. If we can keep the jungle, the jungle will keep us. Architecture without carbon footprint.
Versatility, affordability and ease of shaping bricks to the required size are its main features.
Every visitor to London knows of St. Paul’s Cathedral, but might not have thought how the dome is standing. Barcelona is synonymous with the Church of the Sagrada Familia by architect Antoni Gaudi but very few know what ensures it stands tall. They both use the principles of catenary arch, a rarely used but phenomenally unique concept in construction. Simply stated, if we were to hang a chain, it would hang loose in some curve to stay stable. If we draw up this curvature and reverse it to make an arch along the same profile, that arch will be stable with no other support. That’s precisely what masons of builder Arunkumar got done at Adivaram in Salem.
Once understood how to build, catenary arches are very simple, as has been proved at Auroville. Though the hanging chain has been a popular imagery, it is better to make a large scale template at site to get the arch profile as precisely as possible. Though mathematical explorations for this curve started from the 1600s, marking it physically at site is still the best with our local construction teams.
No single key stone appears at top, with the small curved profile there. With certain parts appearing as if straight, catenary does not have the same radius of curvature all along, but it varies. The first brick resting on ground is laid normal, slowly curving in later, so the load transfer finally happens at right angle to ground.
Even for heavy loads, the top can be thin with thicker base, as such, it takes lesser materials to take the same load compared to segmental or semi-circular arch. To that end, catenary arch has its height or rise more than the span or the width. In contrast, most other arches have their span more than the rise. Centring support can come from a pile of dry masonry, wooden template or a moving framework.
Catenary can start right from the ground, making it easier for the mason to build it up, also enabling better head room heights especially in doorways. Of course, fixing door frames needs extra precaution. While it is very strong along the curve transferring the load, it may crack if any lateral load or side thrust is applied on it as it may happen while drilling for fixing and grouting door frame.
In principle, catenary arches become very handy and contextual where many other arches fail to fit. Being a rare sight, Europe often employed this typology as entrances for public buildings, making them appear grand.
While the visual reasons are still valid, what makes it more appropriate today are its versatility, affordability and ease of shaping the bricks to the required size. In an extended form, catenary vaults create rare interior spaces, while offering a real sight to the eyes. It’s time they start re-appearing in Indian buildings.
The early arches were long poles bent with two ends fixed deep into the ground, series of which gave a perfect shelter.
The day early humans observed thin blades of grass curving down, may be with dew drops still wet and shining in the morning sun-rays, the discovery of arches must have begun. Cobwebs so commonly found then would have been hanging down in a curve, making people think of upturning the curve. There, the arch would have been discovered.
The early arches were long poles bent with two ends fixed deep into the ground, series of which gave a perfect shelter with what we call today as a vaulted roof. Incidentally, even now rural and poor people create make shift shelters in this manner! Arch starts right from the ground up.
However, majority of the later arches were erected upon certain height of the wall, called springing point which could be above the average human height, to avoid someone at the edge of arch from hitting the head into the arch. With such side supports and no more limits to height, there evolved semi-circular, elliptical, segment, pointed, multi foliated and even flat arch.
Among these, a special type is called centenary arch, which is among the very few arch types which start right from the floor like pointed arch, horse shoe arch and such others. With not much of side wall support or springing point needed, it can be erected in a smaller space, still enabling undisturbed movement of people.
European Gothic churches had evolved a system called pointed gothic arches, which is behaviorally different from the catenary curve. Incidentally, many churches of those days employed both the types, in the process popularizing the latter. The gently curving profile of catenary gets generated because of the very method of generating the curve.
When a chain is hung holding on to two ends, it hangs on a curved fashion to stay with equilibrium. Reversing the curve also maintains the equilibrium, giving us a profile that is stable and is called the catenary curve. The geometry of the curve is traced and repeated in building the arch.
Structurally, the load gets transferred in a catenary arch along the curvature and reaches the ground. No lateral buttress, side support and wall below is mandatory. As such, the upper parts can be thinner and lower parts thicker to take greater load or can be uniformly thin all along in case of nominal loads. However, if there is substantial weight to be supported, the wall parts edging the arch at bottom need to be wide enough to take the load.
Catenary arches tend to appear like an inverted English V with no sharp turn. Being a self- supporting profile, that too from the ground up, it creates a unique aesthetic statement. Considering their possible fit into narrow spans, they make excellent option for entrance doors without compromising on movement areas.
That’s precisely what made Sanjay choose this type of arch for his school building at Salem!
The indoor spaces and outdoor styles created by arches are unparalleled both in history and contemporary designs.
The most fascinating chapter in the history of architecture could be to find how humans managed to keep the roof up there. The idea of the shelter must have started then.
It is believed that the earliest method of forming space could be by watching two branches kept inclined to each other supporting each other. So multiple such tree branches inclined together could form a secured space between them, creating a cone-shaped hut. Next four branches kept vertical with horizontal members on top could have created a flat-roofed structure, but this would still be a small space considering the kind of branches one could get – not always straight, often bending in the centre, roof collapsing from the edge and such other mishaps happening.
All this would have changed with brick making, among the earliest technologies discovered by humans, shaping it with sun drying. Soon wall making complete with varied openings like doors, windows and perforations would have followed. One of the challenges was to support the wall part above the openings. That’s when, possibly, arches were discovered.
Arches transfer the wall load by compression, i.e. loads move from one member to another by pushing them vertically or diagonally, and not by tension where they move horizontally too like in a beam. How humans learnt about the strength of curves could be an exciting research topic, for there were very few naturally curved objects to learn from. It’s possible, a playful curving of a twig could have led to trying out a wall opening with a curved profile, creating the first arches in history.
In comparison to horizontal opening topped with flat lintel, the arched top offers a multitude of benefits. Its profile changes with every variation in width and height, with a new look every time. There can be dozens of arch types, while flat lintel is flat forever. Aesthetic theories associated with arches far outweigh those with horizontal ones. The indoor spaces and outdoor styles created by arches are unparalleled both in history and contemporary designs. Of course, along with advantages, also come challenges. If built upon a support system, its strength is unknown until the supports are removed. To construct the arch without such support takes some skill. A basic knowledge of geometry applied to construction is necessary to plan them out, depending upon the span, rise, springing point and keystone on top. The joint between the arch edge and wall needs to be well thought out. Based on the width of opening and load from above, arches may be in one or multiple courses. They also pose problems in fixing frames and shutters, including for windows or doors.
Despite challenges faced, arches continued to rule the world of architecture. When masonry construction declined, being replaced by frame systems, arches were in reduced demand. Now we are realising that framed buildings, especially those in RCC, have higher embodied energy, hence less sustainable. It’s time to revisit arches
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.
Every region in India can evolve a local, contextual and hence ecological architecture, while being contemporary as well.
In aspiring for ecological architecture, too often, we are lost attempting a paradigm shift in our actions, which cannot be achieved unless we adopt the right methods. Methods themselves are determined by the approach, which needless to say, have not changed much during the last 40 years of ecological awareness. It will be worthwhile to re-focus on a few approaches, without which we cannot make headway in green sense.
Image of the building is less important than its impact on the environment:Visual images have occupied centre stage nowadays, be it in websites, fashion shows, TV news channels or in shopping malls. Architecture cannot singularly escape the trend of the time, so most designs are sold with perspective views, rendered images and unbelievably ‘true to life’ computer-generated walk-throughs. Apartments are launched and institutions are inaugurated with media attention. Amidst all this, how often do we hear about the overall environmental impact of the new construction? Very rarely, may be. Stakeholders of every project need to think of ecology before the elevation.
Contextual designs can also be contemporary expressions: The buzz word sweeping across urban India today is ‘contemporary architecture’, a design approach that originated abroad, especially Europe.
Theoretically, ‘contemporary’ should have meant a design belonging to the present time and place, though majority of these structures in India are disconnected from both, primarily following a pre-established western style.
This is not to demean the imagination and creativity behind the contemporary architecture, but to suggest that a contextual design can also belong to our time and place. If designers can take up such a challenge, every region in India can evolve a local, contextual and hence an ecological architecture, while being contemporary as well.
Difficulty of execution should not be the reason to reject an eco-idea: In a fast-paced lifestyle where time has come to mean money, owners and promoters tend to choose designs which are easy to build.
Accordingly, technology-based approaches using manufactured materials get a priority over labour-intensive methods with natural materials. The fine finish with clean lines and shining surfaces appear more enticing than the rustic and handmade. In this process, we not only neglect the carbon footprint of the building, but also the possible construction variety and design range. The ease and speed of doing is becoming both uniform and universal, diluting climate as a determinant of design.
Designing by intuition is as important as designing by calculations:Construction right from early civilisation up to medieval times was deeply rooted in common sense and contextual possibilities. Industrial revolution followed by varied technological and manufacturing capabilities opened up new avenues, formalising the activity into a profession. Naturally procedures, codes of practice, rules, regulations and all the rest followed. The ecological concerns which led to the new direction of sustainable architecture and the green building movement have gone a step ahead with innumerable standards, ratings and calculations. It is ironic that mind is no more the maker of buildings, but systems are. Ecological architecture demands passion as much as profession, intuition as much as calculation
This essay is the 350th in the Green Sense and Eco-Build series, a weekly column that began in May, 2010. With 8 years completed, stepping onto the 9th year, the present and next few essays would try capturing some simple theories that could convert any building into an essentially ecological project.