Tag Archives: sustainable

Micro Houses

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A photo feature on unconventional tiny houses got me thinking about why we never hear of architects designing them in India.  Is it because a very small house is much too readily associated with poverty that we, as a country, are trying to leave behind? Or do we insist on big weekend houses on the off-chance that extended family and friends will come visiting and need to be accommodated?

tiny footprint

Micro houses have a tiny footprint

Whatever the reason, the concept of micro-houses is rarely considered seriously here–although it should be–because because they costs a lot less to build or maintain and, more importantly, they reduce our carbon footprint in a very big way.

We have a long tradition of frugal construction and it’s about time we rediscovered it. Maybe one day, hopefully in the near future, someone will ask me to design one. Or a bunch of them.

The Bottle Light

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bottle light refractionSometimes, a simple idea can be immensely powerful. Maybe the bottle light is not something that makes a huge difference to your life or mine but, for those who live in shanties with little or no electricity, this is a godsend.

screencap from a BBC featureEssentially, one fills a used, transparent, plastic bottle with water and a little bleach (to prevent algae) and sticks it into a hole in the roof.  That’s it. Oh, and don’t forget to seal the edges of the hole.

The light that it produces is equivalent to a 50 or 60W bulb. Of course it won’t work at night but when you think of the dark homes that some of our less fortunate citizens live in, this can—at the very least—brighten up their day.

More:
BBC News Magazine
Instructables
A Liter of Light

The Gaming of LEED Ratings

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We all know that the LEED system can be gamed but that it could be turned so completely on its head was news to me.

greenwashThe Bank of America building at One, Bryant Park, New York has a LEED Platinum rating and was the first skyscraper to ever be awarded this but now, it turns out, it uses more energy per square foot than other building of similar size in all of Manhattan. Wow.

It was hailed as a major achievement by none other than Al Gore who set up his offices there. The basic problem is that LEED is largely based on computerised energy models and “intent”. This makes it open to abuse because it’s easy to purportedly intend something at the design stage and then change the goalposts later on.

Coincidentally, just this morning, I was speaking to a couple of marketing guys who were trying to convince me to attend a “green summit” next month and one of their selling points was LEED. I declined, telling them exactly what I thought of LEED but I wish I’d seen this article just a few hours earlier:

Bank of America Tower and the LEED Ratings Racket via: ArchRecord

Visit to ecobuild India 2013

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ecobuild 2013Yesterday was my day to visit Bombay Exhibition Centre at Goregaon for this year’s ecobuild India 2013.

I was a bit surprised to see some of the participating vendors because there was nothing remotely connected to sustainable architecture in their products.  Others, however, showcased more appropriate stuff.

Was disgusted by a company–which shall remain unnamed–that was promoting artificial thatch imported all the way from Thailand. Can greenwashing get more brazen than this?

On a positive note, I was impressed by products from Corvi and K-lite — coincidentally both are manufacturers of LED lights.  The former have a limited catalogue but all their fittings are dimmable with standard dimmers which is a major plus point in my book.

The show wasn’t very large but I presume it will grow over the years. I just think they should vet the products or else the show, as a whole, will soon lose credibility.

Glaring mistakes

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conventional v/s curtain wall

In hot climates, the overall energy usage rises as you increase the glazed area. Curtain walls, therefore, are highly inappropriate.

I have ranted about glass façades for a long time and this editorial by Sunita Narain of DTE has inspired me to add a couple of paragraphs to the original one.  Among other things, she has written about a recent study by IIT-Delhi which found that, in our hot climate, the manufacturers’ claims of special coated glass or double/triple glazing being able to reduce heat gain are rather hollow.

One of the other specious arguments put forth in an attempt to portray glass curtain walls as green systems is to say that it reduces the electricity consumed for lighting. This is a half-truth. Leave aside the uncomfortable glare that people working inside such buildings have to put up with, let us make a simple comparison.

Consider a 10m² conventionally designed space. Assuming that we don’t take passive cooling techniques into account, the air-conditioning load will be in the region of 3,500W (1 ton).  Lighting the same space, on the other hand, will need just 50W with fluorescents or 40W if we’re using LED fittings.

Now, imagine a similar sized curtain-walled space. The maximum saving that can be achieved by reducing lighting is a puny 50W. However–and this is the big problem–air-conditioning requirements will probably have risen to a whopping 5,000W.  Even with all the specially coated and multi-layered of glass in the world, the total requirement is unlikely to be anything less than 4,500W.

So yes, we may not use as much electricity for lighting but, I’m afraid, the energy usage for cooling will go right through the roof and no amount of marketing spin can get around this simple fact.

Building walls with the rat trap bond

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Just in case I’ve got you visualising rodents scurrying about where they’re not wanted, ease your mind; the rat trap bond I’m talking about is simply a method of laying bricks when building a wall.  It’s similar to the common “Flemish” bond but instead of putting the bricks on their face, they are placed on their edges. This leads to cost savings because less bricks and cement are needed which, in turn, reduces the embodied energy of the wall.

The Rat Trap Bond

Bricks are laid on edge to create an air gap between two layers

Laurie Baker took every opportunity to try and make people realise the value of this method but, by and large, the 20-25% saving in brick doesn’t seem to have been appealing enough.  The rat trap method of construction was popular in England until the start of the 20th century but sustained lobbying by the brick-making industry convinced people that that it was not strong enough to build load-bearing walls.

That is rubbish of course; it’s strong enough for one and two storey buildings as has been proven over and over again by Laurie Baker’s lasting work. But masons too are not usually happy about adopting this system and come up with all sorts of excuses to try and avoid it. I have to admit that, till date, I have not pushed hard enough against their inertia but now I’ve just got one more reason to do so.

For the ShKo bungalow at Karjat, I plan to use the rat trap walls and wanted to know just how much difference they would make thermally. Nobody seems to have done a calculation of the difference — at least there was none that I could find. So, armed with some data from thermal calc and the energy evaluation component of ArchiCAD, I tried to do just that.

Taking just a simple 3m x 3m structure with no openings, I ran a calculation for both types of wall. Result: average U-value of the structure’s outer shell dropped about 15% compared to conventional walls and the energy required for cooling also fell by about 8%. The difference was exaggerated because the model had good roof overhangs to shade the walls.

Still, when you think about it, 8% is nothing to scoff at.  In addition, the embodied energy is reduced quite dramatically and, of course, Laurie Baker’s original reason for using the rat-trap bond still stands — the wall is simply cheaper to build.

Now, I just have to go and steam-roll the masons into learning a new technique.

ShKo Bungalow at Karjat

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The design for the ShKo bungalow at Karjat has finally been completed. It’s taken a lot longer than most because, apart from the complex slope, there was a severe constraint of building within a small portion of the entire one acre plot — the rest is prone to occasional flooding from the adjoining river.

Like other architectural designs, this too makes maximum use of local materials and of passive cooling.  External stone walls are at least 24″ (60cm) thick and provide a formidable barrier to heat-gain even in a place like Karjat.  Deep verandahs on the South and West don’t allow direct egress of strong sunlight from mid-mornings till evening. And high roofs with openings at upper levels allow constant ventilation to take place.

Rainwater harvested from the roof will be collected in the basement that is automatically formed by the sloping land. It will also be used to flood the pool which will not, hopefully, have any chemicals used to disinfect it. The current plan is to do natural filtration but the eventual system will depend on getting a reliable and qualified consultant to carry this out.

Some Renderings

Comparing LED & CFL Fittings

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For the MChi interior site in Bombay (Mumbai), I found some really nice LED light fittings but they are more than three times the cost of identical CFL fittings. Now we all know that LEDs consume very little electricity  and they have an extremely long life but I wanted hard numbers to convince my clients – after all, they are the ones paying for everything.

It didn’t take long… At the light shop, it was pretty obvious that the 18W LED fitting threw as much light as an identical one housing 36W of CFLs.  Frankly I was a little surprised by the 1:2 power consumption ratio because I always assumed it was more like 2:3. However, LED technology is making such rapid strides that yesterday’s facts are already redundant. Putting all the costs into a spreadsheet immediately produced a very compelling argument in favour of the former.

An Example of Total Cost of Ownership – LED v/s CFL

While the life of an LED bulb is in the region of 50,000 hours, the calculation over such a long period (while in favour of LEDs) is rather unfair because even at 5 hours per day, that means 27 years.  Instead, I’m working with 30,000 hours which represents a more realistic 16 years.

Even accounting for the fact that the LED driver (an electronic device that regulates the power that LEDs receive) doesn’t have a 50,000 hour life, the calculation still showed a huge saving.

The calculations here are not likely to remain valid for long because the cost of power is sure to rise even further and that of LEDs can only go downwards.

High-Rises and Sustainability

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SkyscrapersReading an article in Architecture Week about the impact that urban towers have on the natural environment, got me sitting on one of my pet hobby-horses.

I have never been convinced by arguments that high-rises are better and more sustainable than low-to-medium height buildings. I suppose some people get a kick out of defying gravity by erecting very tall structures but that, to my mind, is pure hubris.  Even if we dismiss the recently publicised link between the building of skyscrapers and a bubble economy, I still say it doesn’t make sense — purely from the sustainability point of view.

It may sound anachronistic but the fact remains that living high above the ground makes you lose touch with it.

One of the favourite arguments by proponents of tall buildings is, that they free up open space by reducing the physical footprint of built-up areas  However, at least in the Indian urban context, this is a fantasy that all but the most delusional will reject. In Bombay (Mumbai) where I live and work, every single patch of land is covered to the maximum. What little is left open–because it is mandatory–soon gets swallowed up by parking.  There may be a token play area, swimming pool or jogging track, but blank expanses of unpaved space where children can play freely, are conspicuous by their absence.

The second argument in the urban context is: as land is scarce and expensive, having high-rises propels affordable housing. Bunkum! You don’t need to look beyond Tokyo, Singapore and Hong Kong to realise that cities with the most high-rises also have the most expensive property in the world.

The other favourite argument of the tall-buildings-are-good school of thought is that they reduce energy usage in comparison to low-rise sprawl. Unfortunately, data shows that the opposite is the case..While the energy cost of transportation will certainly be higher if people live in far-flung areas, the overall energy footprint of a high-rise dweller is far greater.

Tall buildings–especially those that have large parts clad in glass–need much greater cooling in a tropical climate like ours.

Why is this?

High-rises have a huge amount of embodied energy in their construction and materials. Adding to that, the energy cost for “lifting” people and water against gravity is constant and very high.  This more than compensates for the additional carbon footprint that a suburban dweller uses — especially if the suburban dweller is able to rely on public transport for the daily commute. Ninety five percent of this city’s citizens do exactly that.

And what about quality of life? Given a choice, families–especially those with young children–would invariably prefer a place where the young ones can grow up with enough place to play. But that is altogether another story.

Further Reading: