ShKo Bungalow

Many people dream of leaving the city to lead a slower, more meaningful life outside it. Few, however, are able to live that dream. Just a stone’s throw from the [RaBV] bungalow here is a sustainable weekday home of a couple who come into the city on weekends.

Site Conditions

Satellite images of the site showing how the flood zone determined the final house location.

Satellite images of the site showing how the flood zone determined the final house location.

Much of this one-acre site is between 1.5 and 3m above the average water level of River Pej, so during the monsoon, the lower section of the plot is often flooded once or twice for a few hours at a time. The initial plan was to build almost touching the river but that would mean building on stilts. Instead—taking into consideration the high water mark of 2005 which saw the worst flood in living memory—we decided to build on a small rise at the other end of the plot. Thanks to climate change, such freak events as the cloudburst of 26th July 2005 are likely to happen with increasing frequency and we must understand and prepare for them instead of brushing these facts under the carpet.

Because of the sloping land we have a large basement

Because of the sloping land we have a large basement

The little rise is next to the access road so the approach to the car parking area is a little steep but, other than that, there are no disadvantages. There used to be a shed on this mound so there were no trees that needed to be designed around.

As the building is on a slope, the extra height at the bottom has been used to create two basements. One stores gardening and filtration equipment along with the rainwater harvesting tanks while the other has batteries, inverters and other electrical equipment for the photovoltaic solar panels.

The foundations and plinth of the bungalow being made of local black stone.

The foundations and plinth of the bungalow being made of local black stone.

Design Considerations for Sustainability

Climate data for the location which helped make a more responsive, passive solar design.

Climate data for the location which helped make a more responsive, passive solar design.

As with the [RaBV] bungalow, the climatic conditions to be considered were hot days and pleasant nights with a strong monsoon. We needed sufficient shade on the South and West sides and this was taken care of with deep verandahs. Air circulation and cross-ventilation were important to eliminate the build-up of hot air. For the most part, roofs are sloping with only a small fraction of flat terrace where the solar hot-water systems are placed.

ShKo Layout Plan

ShKo Layout Plan

Instead of a typical compact layout, this house was designed as a series of spaces with clear zoning of public and private. When seen from a distance–and a height–it looks like three houses in a cluster rather than just one. Central to all three spaces is the court and the open tank. This is not some amoeboid pool for people to float around with a cold beer but a straight 15m strip for exercise. Oh, and it’s a tank because, well, it’s a tank. Water from here goes to the vegetable garden and to many of the trees on this plot.

The clients, currently in their early 50s, want to spend the bulk of their time here exploring their creative side. Accordingly, one of the major spaces in the house is a workshop to be used for painting, stained-glass making and sliver-smiting. There is also a small study, two bedrooms, a utility room, a living/dining room and a very large kitchen.

Materials & Systems

Exposed brickwork, Mangalore roof tiles and windows made from reclaimed wood.

Exposed brickwork, Mangalore roof tiles and windows made from reclaimed wood.

The foundations were constructed from local basalt and the superstructure from local bricks.We discussed the possibility of using fly-ash bricks but the clients had reservations because of the debate over fly-ash being carcinogenic.

Many internal walls were left un-plastered and the roofs had a steel structure with Mangalore tiles on battens without any under-layer.

One of the old wooden pillars

One of the old wooden pillars on its granite-clad base.

Doors and windows were either beautiful old ones that were salvaged from demolished homes or were made anew from reclaimed old Burma teak. The credit for sourcing them all goes completely to the clients. They also purchased five lovely old wooden pillars during their travels, which were incorporated into the design. Since these were only 2.5m tall, we made a tapered concrete base which was then clad with the same grey granite as was used for the adjoining parapet walls.

Energy

All the lights are low-energy, mostly LEDs, while the fans and refrigerator are inverter-type so their energy consumption is also lower than average. As these fans are a relatively new product, it remains to be seen if they stand the test of time.

Bath and kitchen water is heated using one solar panel on each of the terraces. There are also twelve photovoltaic solar panels on the roof of the workshop which provide enough electricity to run all the lights and fans as well as some of the appliances.

Water

The rainwater harvesting filter

The rainwater harvesting filter

A good amount of the rainwater is harvested. Some of it is collected in tanks for drinking water throughout the year. This is necessary as the river, though perennial, sometimes contains urea washed in from fields upstream; even though the water is clean enough for bathing and washing, it is not advisable to use it for drinking or cooking. The remaining harvested rainwater is used for recharging a bore-well that is an emergency backup water-source. Whatever rainwater is not harvested either seeps into the ground or flows directly into the river.

Embedded dual cisterns flush the low-flow WCs and kitchen waste water is sent directly into a soak-pit from where it percolates into the ground.

And finally, some more images
 View through the brick jali  View of the curved verandah
 View of the Tank  View of the court at night

 

Project Participants

Consultants
Structural & Waterproofing Mr. Ratnakar Chaudhari
Contractors
Overall | Civil, Plumbing, Roofing, Painting Mr. Rajesh Phatak
Electrical Mr. Rafeek Shaikh
Carpentry & Joinery Mr. Ramashankar Mistri
Specialised Agencies
Solar Hot Water Solar World
Solar Photovoltaic | Panels, Batteries, Inverters Sunlit Future
Swimming Tank Filtration Oceanic Enviro Pvt. Ltd.

Indian Green Building Ratings

Magic Tricks & Green Ratings

Green Ratings and the Art of Illusion

I’ve been critical of Indian green building ratings, their basic limitations and the fact that they can and will be manipulated. Of course this is not restricted to India alone… the problem is worldwide.

Now, a study by the New Delhi-based research organisation, Centre for Science and Environment, CSE, shows that a number of buildings that had been awarded platinum status–the highest achievable rating of the Indian Green Building Council or IGBC–were in fact barely worthy of any rating at all based on the amount of energy and water they consumed. Interestingly, the study was based on building performance data on IGBC’s website itself. A defensive IGBC is now nit-picking about CSE’s method of analysis but whichever way you look at it, the fact remains that the ratings methodology looks severely flawed.

How is it possible for the difference between the theoretical consumption–on the basis of which the rating is given–and the actual consumption, to be so vast? To my mind, it strikes at the very root of the problem when the system rewards you for your stated intent (genuine or otherwise) instead of rewarding you for your actions. It is all very well to brag that your building has a fantastic green rating but this has to be borne out by actual performance.

The worrying aspect is, the gulf between ratings and reality has ramifications far beyond mere bragging rights.

Many state governments give tax-breaks and extra floor-space for green buildings so the incentive to obtain a certification can be huge.  It is, unfortunately, all too easy to claim one thing at the time of rating and then shift the goal-posts at a later date.

Now that this latest can of worms has been opened, let us hope for a positive change in the way ratings are given and retained. With so many big names and businesses involved, however, there is always a chance that they will collectively try to sweep it under the carpet; and use the old system of discrediting the whistle-blower.

Acknowledgement: image from Pixbay

New BEE Ratings for Air Conditioning

From the beginning of 2104—and in line with past practice—the Bureau of Energy Efficiency (BEE) has updated their rating system for all appliances including lights, fans and air-conditioners. I’m only going to talk about air conditioners here because they are, by far, the biggest guzzlers of electricity.

Energy efficiency is calculated as a ratio of output Watts v/s input Watts. So, if a 3,500W (1 Tonne) air conditioner needs 1,200W to run, then the EER is 2.92.  Up to the end of 2011, that would have made it a 4-star machine. In 2012 and 2013, it would have been considered a 3-star machine. Today, that same machine will be considered a 2-starrer. So yes, as technology improves, the ratings are revised and made a little more stringent—which is how it should be. Have a look at the table below to get an idea of the changes.

BEE Rating History

BEE Ratings over the last few years

While this is good, it may not be good enough.  As this article shows, the entry level for a single star is on par with many other countries but the higher ratings are somewhat below world averages.  Also, manufacturers of inverter air conditioners have long been saying that their machines cannot be rated because they are “better than 5-star”.  Checking the specifications for the ones available in India shows that many of them have an average EER greater than 3.5 but none cross 4.0 even for minimum cooling–whereas the same companies manufacture models for other countries with a higher EER.

This could be because of two factors:

  1. There is not enough incentive to go beyond the maximum available rating since the average person (and even most architects) won’t easily be able to compare two models for energy efficiency.
  2. Models with a a higher EER are more expensive to manufacture and the Indian market is notoriously price-sensitive.

While there’s not much anyone can do about the second factor, the first can certainly be tackled by raising the bar for ratings. As more and more people resort to artificially cooling their indoor environment instead of availing passive cooling (thanks to current architectural trends) our energy situation is getting more and more precarious.

The Changing Face of Lighting

LEDs are changing the face of lighting

LEDs are changing the face of lighting

My first encounter with LEDs was for a school project where I wanted to use one as a little red indicator. In those days, they were simply Light-Emitting Diodes, nothing more. The though that they would, one day, be used as a source of light didn’t even remotely cross my mind.

In the last few years, however, LED technology has taken giant strides and the early problems like inaccurate colour rendition and a limited light-cone have been, to a great extent, sorted out. Added to that, the costs–which used to be very high–have come down to relatively affordable levels. While they are not, still, competitive with fluorescent lights, the day is probably not far when LEDs will replace them.  Even at today’s prices, they are already more economical in the long term.

With their small size and favourable physical properties—they run cool, have a long life and are able to vary their colour—LEDs have made it possible for lighting designers to come up with some very original creations.

Image derived from | https://en.wikipedia.org/wiki/File:On-state_off-state_white_LEDs.jpg

The Bottle Light

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

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

Glaring mistakes

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

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

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.

View from the gate

Picture 1 of 5

The entrance is set within a recess adjoining the car-port. Deep roof overhangs protect most walls from direct heat-gain. All external walls are at least 24" (60cm) thick and made of local stone to keep the interiors cool even in summer.

SVAGRIHA – a simplified version of the GRIHA Green Rating System

They’re calling it “Small, Versatile, Affordable” GRIHA – a less complicated green rating system for projects less than 2500 sqm. in area.   Quoting from the email they sent me:


ADaRSH (Association for Development & Research of Sustainable Habitats) is pleased to announce the launch of

SVAGRIHA
Small Versatile Affordable Green Rating for Integrated Habitat Assessment

A Rating system for small homes, offices and commercial buildings with built-up area less than 2500sqm

SVAGRIHA is a significantly simplified, faster, easier and more affordable rating system and will eventually function as a design-cum-rating tool. It was required that attention be paid to smaller buildings in India which although have small individual environmental footprints but their cumulative effect is far bigger. SVAGRIHA has been designed as an extension of GRIHA and has been specifically developed for projects with built-up area less than 2500sqm. SVAGRIHA can help in design and evaluation of individual residences, small offices and commercial buildings. The rating comprises of only 14 criteria (instead of 34 of GRIHA) and the interface comprises of simplified calculators. These calculators can be filled using information from construction drawings like areas and quantities of materials. This can be done easily by the architect of the project. Once completed, the tool will tell the consultant the number of points that they are able to achieve in that particular criterion and provide recommendations for any improvements in order to improve the environmental performance of the building.

Process of SVAGRIHA Rating

  • Registration of project with ADaRSH
  • Submission of completed calculators, drawings and other documents as required (quantity estimates) to ADaRSH
  • Assessment/Review as per SVAGRIHA
  • Site Visit and due diligence check post construction (mandatory)
  • Evaluation by GRIHA certified Evaluator
  • Award of Rating.

Note: The site audit to check compliance will be done once the project is complete and all equipment to be verified are installed.

For more information please visit www.grihaindia.org


GRIHA is the national green rating system for India developed by TERI and the Indian Government. I’ve always felt that GRIHA is far more suitable for us than (the more popular & better known) LEED rating system.

SVAGRIHA has just 14 criteria compared to GRIHA’s 34 and can act as a good checklist at the design stage.

SVAGRIHA CriteriaSVAGRIHA point groupsLooking at the point groups, I’m happy to note the weight given to Energy and Water conservation. At the same time, to achieve a rating, the design must achieve minimum standards in all categories. So while they say that 25 our of 50 points will give you a one star rating, adding up all the minimums means you actually need at least 28 points.  And finally, the table below shows the star rating that can be achieved.

SVAGRIHA stars