Monthly Archives: November 2013
Let us walk into a modern office or a swanky mall or fine dine restaurant. Let us look around observing every item and material in sight. Possibly, more than a third imagine this as a revelation — human beings have been on a fast track mode discovering and inventing new materials like never before since the birth of civilization.
Was society of the past any less than ours because these marvellous materials were not available to our forefathers? Strangely, the answer is no. They also led a life full of joy and grief, gains and loss or hopes and frustrations just like we do today.
How many of these materials are for our needs and how many for greed, comfort or luxury? Are these justifiable by sustainable standards? Are we a party to depleting earth’s resources when we buy an item?
Such discussions did not appear important until recently, as we were oblivious to the reality of the limited resources we are living on. The word “green”, coined less than two decades ago to suggest an alternate developmental model in contrast to our dangerous ‘red’ approach, has now come to stay to symbolise any human effort in saving the environment. Green also connotes the visible ecological cycle, living as against dying, and continues the efforts of nature conservationists which started much before it was adopted by the construction industry.
The green building movement, as it is popularly called, was initially termed eco-friendly architecture with varied design parameters like light, air, space, maintenance, local style and affordability. Low-cost buildings, a term being used for decades, also hints at sustainability, though today it is better referred to as cost effective building. As such, the word green could be a new term, but the intentions have been around for a while now. The idea of Green Material continues similar affiliations to the intent of energy efficiency and sustainability.
Incidentally, the energy consumed in a building by the construction materials may not cross 20 per cent of the total energy the building would have consumed. Likewise, the share of material cost is only a part of the total project cost. However, construction materials cause depletion of non-renewable resources, create non-recyclable wastes, consume energy for manufacturing.
Today, many new materials are being popularised by marketing and advertising to achieve greater market share. We get only minimal data about what good or harm they do to nature. Hence, we are facing the immediate imperative to study and understand materials towards the right choice, if we have to keep the sustainability movement going on.
Today most tanks are made from synthetic plastics with high embodied energy, produce much waste in production, cannot be cleaned easily and heat up the water during the summer afternoon just when we need cool water. The traditional brick water tanks have solid concrete roof with all the strength and security associated with concrete, which are not required for water tanks. We lift up the tank level at extra cost, with no other benefit but the extra height. Often tanks are so small that frequent pumping up become a necessity or they are too large with stagnant water. In many such ways, we are not getting the best from overhead tanks.
For a small family of four, we do not need more than two days’ supply of approximately 1,500 litres atop the house. The water consumption per person per day is around 150 to 200 litres, so in case of large storage capacity, daily replacement will be small, leaving the old water in the tank. Instead of the RCC roof top, we can have a metal sheet lid framed in M.S. angles that can be lifted up like a car bonnet. This drastically reduces the cost, makes the job simple and enables anyone to get into the tank to clean it. Most people do not periodically clean the tank, for it’s a cumbersome procedure, so the lid concept eases it out.
If the tank is placed in the corner of the building, we get two edge supports and can save on structural cost with a diagonal beam. To get the water pressure for solar water heaters, we need a minimum height of 6 ft., which can be further raised to get 7 ft. underneath the tank. By a small extension of the tank slab, we can actually get a small room underneath for storage, stay, study, wash, pressure pumps or as may be needed. On the cost front, this room would come at a nominal extra cost, but contribute to varied activities on the terrace.
Taking fewer large diameter pipes and then branching them off into multiple taps instead of taking a separate outlet pipe for every tap is another measure to save on plumbing. Let all pipe connections be accessible for future inspection. Replacing G.I. pipes by the new generation pipes has decreased the need for repairs.
Being a manufactured and marketed product, the PVC tanks have surged ahead of traditional brick tanks in popularity, though they come with numerous problems. The only possible problem with brick tanks is seepage due to bad workmanship, which can be mitigated by some attention. Plastering the inside with chicken mesh eliminates the seepage, while anti-fungus paint keeps it clean. Water in a brick tank stays cool and is any day healthier.
What is the nightmare for designers as a house nears completion? One answer is overhead water tanks! If they happened to be visible from the road, no design seems to be convincing enough. Possibly so, most house owners do not bother about how it appears, leaving it as a sore thumb rising from a beautifully designed house.
Besides the matter of aesthetics, the very idea of high-level water tanks is an energy consuming proposal. The electricity required to pump water from low levels to cities at higher plateau, then take it from ground level treatment plants to large neighbourhood water tanks demands a good share of the city electricity supply. Though the supply to individual sites is on gravity flow, imagine each building again pumping it up – the whole exercise appears to be against the natural principles of water flow. Though the story of reaching water from a far-off river to the house kitchen is exciting as a civilisation achievement, it is also a story of battling against nature, consuming resources.
Many cities around the world are not dotted with water tanks forming their skylines, yet get day long water supply. From the treatment plants or a nearby surface level water sump, water is pumped continuously such that the houses need neither underground sump nor overhead tank. Just turn the tap on to get water anytime. It has been studied that such an arrangement does not necessarily increase water consumption, makes the pipes last longer avoiding the dry and wet conditions, avoids duplicating storage at every level keeping the final supply fresh, and saves lot of money otherwise spent by individual families. Above all, it negates the illogic of pumping water up the sky twice, against gravity.
Direct pumping is possible at the house level also with pumps connected from the sump to outlets. Whenever we turn a tap on, the pump automatically starts pumping water and stops when we close the tap. This measure avoids the need for an overhead tank and reduces the overall running length of pipes, offering monetary savings. Of course there should be regular power to ensure pumping at any time.
Inadequacy of supply
The present approach of having tall and large water tanks supplying water for a few hours to a large area means inadequacy of supply by gravity flow, pumping as a necessity, provision for sump with tank and longer lengths of pipes with pressure loss. One alternative lies in smaller water tanks spread over smaller areas to ensure full day water flow by gravity such that no house needs to build either a sump or a tank. When we feel the scarcity of water we tend to store it, only to use it later carelessly, but an assurance of regular supply automatically regulates the consumption as well. There is no proof to claim that longer supply means greater consumption, for everyday we all need water only for specific purposes, hence only in specific quantities.
The Green Sense column, now being published for over three-and-a-a half years, elicits many follow-up mail responses, directly suggesting its usefulness to the readers.
To that end the role of a newspaper essay is well served and acknowledged. The challenge often goes beyond the first round of publication when the readers post enquiry mails seeking further information.
Incidentally, these essays are structured more as subject introductions and basic information, without the jargons of details and expertise.
As such, while every essay specific to an idea can be shown to the project team of the reader including architects, engineers and builders, the idea cannot be directly executed unless the team does further studies.
A related question has been where have these ideas come from or from which book or website the points have been taken? Except for a few essays on bamboo, wind turbine, arch foundation and few more, all the rest are written by the personal experience of the author, having designed buildings for the last 18 years using those ideas and seen their execution through skilled teams of contractors.
To that end, one should be thankful to a wide range of clients who sought thinking out-of-the- box and accepted alternative ideas; equally well to other Bangalore architects like Kanade’s, Jaisim, Chitra, Mistry’s and research institutions like ASTRA, Mrinmayee and Gramvidya.
Since books or web sites were generally not referred to, no in-depth data was collated or supplied through the essays. Passing on the personal knowledge to the public realm was the basic objective, rather than turning the readers into subject experts. Naturally, the essays evolved as a kind of first read, such that interested readers can do further exploration as required individually.
Every region in India has a local tradition, which is the richest source book for ecological designs. While modern buildings are increasingly replacing the older types, a revivalist interest has also picked up, hence finding subject experts on local, vernacular ideas is not very difficult. Anyway, a large number of traditional structures are amidst us even today, like an open air museum of ideas for anyone to pick up ideas from. A comparable source of skill lies in the senior generation of masons, carpenters and such others. Every region has at least some people and organisations with alternative ideas. Many institutions have research and documentation facilities, findings of which are regularly published or posted on their web sites.
Readers can search for The Energy and Resources Institute (TERI), Indian Green Building Council (IGBC), Central Building Research Institute (CBRI), Hunnarshala Foundation, Govt. departments for renewable energies, ECBC, varied initiatives at Auroville, HUDCO, regional building centres often called as Nirmithi Kendra, Laurie Baker Building Center, and COSTFORD and many of such centres offer data, designs and knowledge on green buildings and sustainable practices. Besides public bodies of the above kind, many private design consultants, now in increasing number, are offering eco-friendly ideas for those who seek them.
We only need seekers for these ideas in larger numbers, towards a better future.
Sourcing information about how to build has always been in the forefront of cultural and constructional challenges.
Majority of us look around within our village or town to pick up ideas, take some advice and adopt them to our needs. Historically, this has been the most common practice, which led to a body of knowledge today we call as the local vernacular tradition. Mostly owner built, limited to regional materials, suited to the family lifestyle and comforting during the harsh seasons, architecture evolved as a derivative of cost, culture and climate. Incidentally, these three principles need to continue even today as the basis of green buildings.
The last few hundred years have seen the evolution of skilled people such as carpenters and masons. Also, during the recent decades trained designers called architects have also emerged, to assist the owner in the act of building. Till recently, these two were additional sources of knowledge other than the local wisdom. Nowadays, we can also get ideas through books, journals, websites, research institutes and plethora of other sources. The challenge is no more about getting information, but it is all about being sure how eco-friendly they are.
Here lies the contradiction – much of what is being doled out as green and eco-friendly are really not so good with nature, judicious for the purse or safe for humans. They are market-savvy ideas, guised under visual attractions, speed of execution, easy maintenance or international image, often with good profit margins for the manufacturers. We as consumers can get all information about the materials through designer brochures, updated websites and efficient marketing executives, but virtually no information about what quantity of earth resources the specific material consumed, what could be the waste generated during the process, how this waste gets treated, what happens to the leftover production stock, what could be carbon footprint and finally what is the embodied energy of the material.
The above contradiction is not entirely due to the profit seeking construction industry. All of us are swimming today with the flood of information, but cannot glean what we really need from around us. There are is no unanimous agreement about sustainable approaches nor do we have proven data on what are harmful and what are not. Given this context, adopting nature friendly measures in our buildings becomes a challenge despite our good intentions to that end. As such, it is imperative of our times to evolve yardsticks of judgment and choose where to source meaningful ideas from.