The Initiative for Green Habitats represents a long term commitment towards providing solutions for the creation of Sustainable Built Environments. This blog attempts to provide an insight to our views, commentaries on our work, ideas that we are working on, and provoke thought where there are more questions than answers.
Showing posts with label Sustainable construction. Show all posts
Showing posts with label Sustainable construction. Show all posts

Friday, September 21, 2012

Towards a zero footprint architecture

Our decisions hold the key to this 21st century environmental enigma.
Is it really possible to go 'zero'?

Consider this. Every act and process putting together a building nowadays involves huge amounts of energy and impacts the environment. Let us assess a few areas:
  1. Utilisation of materials to build- virgin, reused, recycled or otherwise
  2. Extraction of the raw materials
  3. The transportation of these materials
  4. The manufacture of building materials..
  5. The generation of direct and indirect wastes, and pollution.
  6. The consumption of materials in operations- water, energy, fuel, etc.



When we look back, not too long ago, say just over a 100 years, we find that there were hardly any emissions of any kind involved in the usage of materials for building. Energy for extraction, or the synthesis of materials involved the usage of higher degrees of human labour to compensate for any other form of energy. This was so stark that the construction of large institutional buildings like forts, palaces or temples resembled the efforts put in to build the dams of today. Having said that, in India we are still a labour intensive construction industry... which is not altogether a bad thing considering the great amounts of employment that it generates. What is required though is a drastic improvement in working environments and skill levels.
Surely some CO2 emissions and environmental fall outs did result from some construction activities (the institutional causing greater damage than the vernacular). For example, the burning of bricks used as building blocks has remained much the same as today, with vast amounts of wood/coal being used to fire the brick kilns. Sun dried bricks, or Compressed Soil Stabilised Blocks, or, rammed earth walls, using lime as a mortar, need no firing and use solar energy. If we are able to tap into renewable energy sources for construction or material production, we could make material production and usage emission free. 

An iron ore mine in South Goa that has eaten into the biodiversity rich Western Ghats!
Extraction is altogether a different matter. The energy of extraction today involves the spending of large amounts of energy for mining, excavating, etc. In earlier times, the low demand (non-institutional) dictated the rate of extraction, but a market driven new world economy exerts too much pressure here. To keep up the indices of performance, more material is extracted. I have written about this in another blog post. The methods of extraction have also changed significantly. Granite is now blasted out of the ground, while one method from the past used in some places even today , involved the insertion of wooden dowels into the ground and soaking them with water, which would expand during overnight cooling and crack the granite in the desired size. The extraction of stratified rocks like marble and sandstone has seen a similar change, with the inclusion of heavy machinery  against the use of skilled manual labour who would split the marble along its grain, by driving wooden/metal  wedges into the rock. Today, more often than not, vast areas of forests are cleared to reach these raw materials. This leads to the destruction of CO2 banks and the release of these green house gases due to the rotting of this cut-down biomass. Also, forests are sponges of the earth and ensure a healthy water balance, by keeping the ground well hydrated and holding together the top-soil. Once removed, the land gets parched and erodes the soil of essential minerals for sustaining plant life. Dependent fauna are the immediate victims. The massive scale of raw material extraction today has impacts that affect the region beyond the immediate context. I am not too sure if there can be a zero impact extraction method as an alternative, but perhaps we should look at the kind of raw materials that we consume as a start. A larger use of waste as a raw material, easily re-fashionable building components, a more spread out usage of material according to geographic regions might help.

With a booming modern day construction scenario, such sights aren't
that uncommon, but what is not visible to all is the energy consumed!
Today's building materials have often travelled many a mile to get to our construction sites. We do not bat an eyelid about this specially since all aspects of our lives have ceased to be limited by matters of distance. Being a relatively large nation, geographically speaking, industry has spread its tentacles close to their source of raw materials. Vast transportation networks and corridors constantly feed stocks close to our sites relentlessly. The effort to pick up these materials for construction is usually from the local outlets, obscuring completely the energies that go into getting those materials there from the points of manufacture. There are other forces that define the distances our building components travel...  Global aspirations of the project initiator may attract faucets all the way from Europe, or, kitchen equipment from Italy, or, Paints from Korea and so on. This very global economy sometimes also creates a seemingly  improbable yet financially lucrative incentive to by overseas.... a whole lot of building materials today (as many other goods) originate in China.
Over a 150 ears ago, such sourcing would have been the exclusive habit of the kings!! The masses would invariably build what was available locally, therefore more affordable. While it is easy to talk of the use of locally available material, we ought to compliment that with supporting market incentives, upgradation of skill-sets & technologies, and most importantly a sustained education and advocacy effort to sensitise people to the ills of stretching these geographic limits. A few disincentives like a transportation emission tax could provide an encouraging nudge. 

Manufacturing today is a complex science, involving complex systems, resulting in complex products.... and ever so often a set of complex (read harmful) residues/wastes. In the yearning for 'long-lasting' solutions we have taken complex engineering to higher and higher levels, and devised materials that are made of  unbreakable bonds. Be it the plastics that cater from protective sheeting to transparent screens, the laminates for flooring or cladding, the chemical veneers for roof and wall covering/protection, the non abrasive tiles that span our floors (and walls),.... the resulting side-effects are equally strong in their environmental impacts. High energies needed for manufacture of these complex bonds result in high CO2 emissions, Chemical by-products take a toll on our air, soil and water as emitted pollutants, and the products themselves end up leaching poisonous chemicals into their built environs over their lifetimes. For example, Volatile Organic Compounds like lead, Mercury and Arsenic are spewed by most chemically coated surfaces from paints to laminates to carpets. Bituminous compounds used in waterproofing (and in road tops) break up relatively quickly and leach into the ground, contaminating the local aquifers. Perhaps the trick is to stick to near natural states of materials, like earth for construction, bamboo/wood for building structures, lime/mud for wall plaster, stone as cladding and building block, etc. Physically fashioning a natural material to suit an application involves no further chemical contamination, whereas chemically altering compounds is saddled with these toxic extras.
The sun sets behind the smoke stacks of one of our many industrial backyards.
There are scores of materials today that claim to be energy efficient. But we have to put that in context. Energy efficiency in usage (while good) need not be energy efficient in manufacturing. Also, energy efficiency only implies a betterment from the current benchmarks, and does not mean that they are energy positive. Furthermore, when one refers to a zero energy building, a common term today, one normally means the net energy consumption during its lifetime, which does not include the energies that went into the making of the building and its building components. Depending on building use, the energy in building (or embodied energy of building) could be equal to the total energy consumption of the building in its operations. Thus the often used term for zero energy building refers mainly to the operational energy equation, and is not therefore truly zero energy.

I have covered the topic of consumption in an earlier post, and it takes very little to understand that consuming less would have a proportionately lesser footprint. So far, we have seen that we have big decisions to take in the choice of materials to reduce the upstream environmental impacts during extraction, transportation, manufacturing and utilisation. Is it possible to occupy a truly zero ecological footprint architecture? Many examples exist, in our past, in our rural hinterland and in some truly commendable contemporary projects, that hint at the fact we can get there. The necessary ingredient for that though is a complete overhaul of our thinking and gaining insights into our every decision in the building process, from design to occupancy. I remember a Star Trek episode which spoke of a race that chose a passive and low tech living against the high-tech unbridled alternative, for very much the same reasons... to preserve a way of life! 

Tuesday, March 6, 2012

Kicking up Dust - Linking construction activity to health

A walk in the (dusty) clouds.... Where? Our fast growing cities!
It is high time that we give importance to health issues due to construction activities. The responsibility of professionals associated with the construction industry goes beyond the merits of the end product. The general well being of those who live and work within and beyond 'the site' HAS to be our responsibility. Look around you and all you see is apathy. Work being carried out with no concern for the fall outs.
Dust pollution has gone up visibly in our rapidly developing cities, and this is taking its toll on it's inhabitants. While it puts construction personnel at the highest risk, it is an increasing factor for the rise of respiratory diseases in our cities. A statistic by the Karnataka State Pollution Control Board puts construction generated dust pollution at about 14% of the contributing factors for Suspended Particulate Matter in the air. In the construction industry the most prevalent of these diseases are chronic obstructive pulmonary disease (COPD) and asthma and silicosis. However, chronic fungal infections (carried on dust), interstitial lung disease, silicosis which increases the risk of Tuberculosis, and even carcinoma have been stated as possible fall-outs of dust related health issues. This can be verified by a simple Internet search.  It is appalling that it has not yet become a topic of public debate.
The major contributors of dust are bad practices at construction sites, callousness of workers, unprotected storage of construction material & debris, shoddy maintenance and incomplete works. Movement of vehicles to and from  construction sites, and those carrying construction material and debris, without adequate checks like watering down at points of egress, cause further dust pollution. Transporting materials without proper covering  spreads dust way beyond the peripheries of the construction sites. If we identify these points of origin, we should be able to put in place checks to curb dust pollution.
A quick perusal of the Karnataka Pollution Control Board's website (could apply to other cities as well) shows a stark picture. For a city this large, only 6 points have any recurring statistics at all! This is hardly enough to draw a clear picture of the the extent of air pollution across the city, let alone construction related dust pollution. There seems to be no monitoring being carried out near major arteries where large scale construction projects are underway (metro, underpasses, flyovers, road widening/laying, etc). What we need is a more wide-spread and dynamic data gathering and sharing process of air pollution levels which can be monitored closely. This would also also enable the linking of pollution levels with specific activities, which can then be a support for taking action. While there are clear benchmarks for acceptable levels of emissions from DG sets for example, there don't seem to be any clear norms for what ambient dust levels should be for construction sites in specific. Broader SPM (Suspended Particulate Matter) and RSPM (Respirable Suspended Particulate Matter) figures are available, but none for points of origin (like construction sites) where concentration levels are much higher.
From roads to building sites, we see construction debris strewn about and a haze of dust. This haze does not restrict itself to the site and is spread by air movements to cover a wider area. This is evident in the browning of plants, and parked vehicles around the site, often beyond visible distance. While it is shocking to see construction workers working without protective gear, what is greater concern is the scale to which this problem has grown. 
Construction dust affects all of us in more than one way:
  • Most importantly, it affects general health, leading to a slew of respiratory disorders, eye/throat irritation, etc.
  • It causes damage to property
  • It leads to environmental deterioration... air and water pollution
  • It creates a poor quality of life and workplace... both basic needs of citizens
It is very surprising to see that precious little has been done to reduce this growing problem.The 'Polluter Pays' model has been discussed ad-nauseum in various fora, but dust pollution due to construction is limited to only a single point stipulation to exercise control in the bye-laws and earns one credits in one of two green certification for buildings in the country. Nearly all construction sites are devoid of even signage warning against the generation of dust, or, the wearing of adequate masks. A simple search on the 'AIR (PREVENTION AND CONTROL OF POLLUTION) ACT, 1981', (or its amendment) does not have the word construction or the word dust in it! Surprising. Here are a couple of definitions that caught my eye:
  • "air pollutant" means any solid, liquid or gaseous substance 1(including noise) present in the atmosphere in such concentration as may be or tend to be injurious to human beings or other living  creatures or plants  or property or environment;  
  • "air pollution" means the presence in the atmosphere of any air pollutant;  
Doesn't dust qualify as an air pollutant? And wouldn't construction be seen as a major contributor of dust pollution? On a single page document on the KSPCB website, termed as 'Measures to combat Air Pollution in Bangalore city' there is no mention of construction dust. Their entire pre-occupation is with types of combustion fuels. I think Pollution Control Board/s have to wake up and take notice of construction dust as a major contributor to respiratory diseases.

Here is what we think ought to be done:
  1. Draw out a policy on construction related dust pollution. 
  2. Make dust pollution a statutory offence. It does amount to serious negligence on the part of the executing agencies.
  3. Clearly spell out the guidelines to be followed strictly at EVERY construction site and in ALL construction activities.(This is not that difficult. There are very clear processes, and measures that can be followed to ensure compliance. Of course this involves extra effort and a wee bit more money, but the gains are more than significant.)
  4. Educate the public of their rights and their right to complain. Make grievance addressal a fast-track forum.
  5. Have a working monitoring mechanism with greater powers with local bodies and not merely some centralised body.
It would be important to note here that our cities reflect us. To a great degree, our cities are in the state they are because of how little importance we place on excesses like dust. The lesser we complain, the less we take steps to demand basic health standards, the more dust is going to get kicked up.

Wednesday, December 21, 2011

How green are cement, steel and bricks ?

I saw this query on an Internet group a while back and felt it was important to pen down my thoughts on this. I have been talking about this for a while now, but never got down to writing about it. So here goes.
Cement, steel and the standardised burnt clay brick

To arrive at a better understanding on how green these materials are, one would have to address this from different perspectives:
  • From an embodied energy perspective
  • From a scale of consumption perspective.
  • From a regional impact perspective
  • From a construction vs livelihood perspective

Embodied Energy
An IGH Projection
Cement and steel are processed materials, that consume a lot of energy in their making. Modern day Cement mainly is a mixture of various components, essentially lime, and other binders.
Cement from the time of the Romans, has been a binder material used for making building components adhere to another. Lime was an crucial part of this mix. Other pozzolanic materials like volcanic ash, etc were also added by other groups.  In pre-industrial times, the production of cement did not involve much more than animal driven and human labour.... from the extraction of raw materials right down to the production of the cementitious mix. Today of course, cement production involves the use of generated energy (driven by electricity, diesel, coal, etc)
Steel in construction is an industrial era contribution (barring a few earlier usages), and has become a mainstay in all forms of construction. In the 5000 plus years of civilisation history, it is interesting to see that a material that was never ever used in construction , has become an integral component of all construction in just over a 150 years (not that this bad in itself)..
A projection by IGH
Burnt Brick production has remained the same over the past many centuries, but the standardisation since the British times has seen an inefficiency in the burning process. In earlier times, bricks came in all sizes and shapes primarily due to the differences in clay compositions between regions, resulted in better burning. Today, the standard burnt clay brick is 9" x 4.5" x 3", all over the country.

A great amount of energy goes into the manufacture of modern day cement, bricks and steel .There is a dearth of consistent data on the applicable embodied energy for these materials, primarily due to the varying conditions of production, sources of energy and scales of operations. However, if one does consider the potential contribution to CO2 emissions by these materials used today, the significance is apparent. On average a 1000 sft residential unit (independent house or apartment) would result in the emission of anywhere between 45 to 72 MT of CO2 into our atmosphere. In the context of over a 100 1-million plus population cities in India alone, and with an ever burgeoning urban population this is significant.

Consumption
A file picture of iron ore mining activity in Bellary, Karnataka.
Photo: M. Ahiraj, The Hindu
What is even more significant is the rate of production of these materials in the last 100 years (post the industrial revolution). The modern global economy has created a mad rush to urbanise and has pushed rural populations to cities in search of greener pastures. The combined effect of Business, Growth and Migration has led to a boom in construction activity for business, residences and infrastructure to support this. The rate of consumption is fed by a hitherto unseen rate of extraction of raw materials and production of construction materials and components.
This consumption has great side effects. Beyond the CO2 emissions, up-the-chain environmental damage due to pollution, afforestation, and harm to ground water is grave and has resulted in changing the surface of our planet like never before. Transport of these materials has meant the creation of further construction corridors and which has led to massive atmospheric pollution due to petroleum exhaust (incidentally, never before has petroleum been burnt in such a scale as in this period). The large scale construction activities that we see in our cities and towns today create dust and air-pollution, causing health hazards like never before.

Regional impacts
Change is inevitable, but it is the nature of change that has to be examined. There has been tremendous and rapid transformation in the way we build, originally from a construction material/system point and eventually in the forms that the architecture has taken. This change is more of an imposed change, fuelled by industry set up in independent India and also by the great aspirations of the Indian masses. Agendas set by early politicians and subsequent governments further added to the modernisation of India. This trickled down to built form, but has resulted in a complete alienation (and extinction in many cases) of building traditions and regional architecture. Cement, steel and the modern day brick rode this wave of change. RCC, cement and 'sariya' (reinforcement steel) are now household words, and almost every contractor and mason knows how to work with these materials (at least has a working knowledge). These materials are now unshakeable and integral components of construction in urban India. They are considered as the solution to all evils of what is perceived of as 'kucha' works. So deep is the knowledge loss that current day construction workers hesitate (and refuse) to apply traditional materials and systems that were prevalent only half a century ago..
Construction labour at a site
A disappointing outcome of the latter half of the 20th century in India is the emergence of a monoculture in architectural form that has taken over its urbanity. While nationhood united diverse people and cultures, the direction construction has taken ever since is leading to the wiping out of this very essence of diversity. What is more ironic is that numerous studies done over the past couple of decades have shown the limitations and inability of this architecture/built form in providing appropriate occupant thermal comfort, colour and character, and so on. Yet we persist. While change that is inherent (or from within) is understandable, un-reined change with no care for the consequences is not.

Construction vs livelihood
Resources followed the money. Skill-sets needed for RCC construction were simple and were honed, whereas traditional building know-how became unviable over the years. Industry supplied cement, steel and the standardised burnt-clay brick to every nook of this country, while traditional skills were limited to small regional (maybe even sub-regional) extents. Therefore, a moving populace (mostly rural folk looking for better incomes) picked up what would earn them an income irrespective of where they locate to, and moreover there was a lot of jobs for the picking. This scenario is still unfolding, killing our building traditions steadily.

We see that this illustrious group of modern day materials (cement, steel and the standardised burnt brick) has a high embodied energy, cause immense environmental damage (both up and downstream), has altered the regional diversity of our building traditions and systems, and is continuing to wipe out the livelihoods of traditional crafts persons. The 'Business As Usual' scenario of modern day construction materials and systems  is unsustainable and needs an overhaul. Alternatives to these materials and construction systems are urgently necessary in the context of the ecological tilts that such human activity has caused over the last century and a half. Small gestures of reducing a bit of this or that is not going to add up as anything significant. The time for a complete re-think to redeem ourselves is now.