Monthly Archives: May 2018

The approach is crucial in construction

GREENBUILDING

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.

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Truly green, and stylish too

Cob walls can take any shape, including curves, sculptural forms and furniture profiles.

05bgp-greensensGQL3TR0TT3Anyone who explored how our past generations built is bound to have discovered mud walls, be it of Didi Contractor up north at Dharamshala or Laurie Baker in deep-south Kerala. We owe much to such pioneers who re-created our confidence in eco-friendly approaches. However, the introduction of newer ideas has eroded societal belief in traditional systems, including the cob wall, which is among the greenest material with not even cement as an additive.

Soil mix with approximately 20% clay, 20% silt and rest sand, a proportion that can vary slightly, is ideal for cob. Chopped straw, rice husk or such non-decomposing fibrous binders are added to control cracking, and lime is added to make it termite proof. Once this smooth mix with no lumps is added with water, it shapes well as a ball or elongated egg. Testing it is important, checking for consistency by how it cracks while dropping, breaks while being pulled or feeling its stickiness to hand.

These handmade lumps are placed side by side, gaps filled with soil, pebbles, or burnt brick pieces. The surface can be leveled by hand and compacted by hammering. Each layer is checked for consistency in width, say 2’ or at least 1’ 6”, and allowed to dry before next layer is placed. The side of the wall needs to be smoothened before it dries too much using wooden leveling bar with the sharpened edge or even hacksaw blade.

Protection

Exposed cob is not advisable anywhere, especially the lower part of wall vulnerable to erosion by rain, where we may use stone. Since the soil mix is unstabilised, walls facing lashing rain would also need protection. Besides, the wall surface tends to crack, more initially and slowly later on through one full cycle of all seasons, i.e. up to a year.

Given these reasons, cob walls need crack filling with the same mix, later plastering with mud stabilised with cement and quarry dust. The final coat can be with lime or left as mud wash with oxides for colour effect.

To locate openings, we need to fix temporary shuttering, to be removed once the wall is shaped. Stone or wooden lintels suit the cob most, though thin precast RCC lintels can be inserted above very wide openings, to be finished with mud later. Electrical conduits can be fixed externally on the wall, though they can be embedded by making grooves like in normal construction.

Being a loamy material, cob walls can take any shape, including curves, sculptural forms, and furniture profiles. Feasibility of cob depends much upon space available for wall thickness, local climate, availability of the ideal soil mix, local precedence, the speed of construction expected and of course owner’s acceptance.

In India, we do not document our works adequately and provide knowledge to others. Given this, the documentation at Sacred Groves is really remarkable, besides which workshops by Thannal and website postings by many consulting architects today provide basic information if one desires to revive cob walls.