Monthly Archives: May 2015

Essence of eco-friendly homes

We have to minimise the damage to nature and convince ourselves about alternative design approaches.

30bgp-green_GIE_30_2421766eWe are going through a time when most people have no time, as such it is imperative that we not only have elaborate essays but also brief pointers towards eco-friendly architecture. We know that every construction can happen only after some destruction; as such theoretically architecture cannot be sustainable. It’s equally true that the need to construct is a valid human activity.

As such, all that we can do is to minimise the damage to nature and convince ourselves about alternative design approaches. The following could be good starting points to that end:

Minimise manufactured materials: Do we know why brick overhead water tanks have given way to plastic-based tanks? These manufactured tanks need to earn profits for everyone from producer to retailer, hence get aggressively marketed, despite the resources they consume or wastage they cause. In contrast, no one markets brick tanks, instead face wrong propaganda against them, resulting in a slow death. Every manufactured item has the same story – they eliminate the natural, local materials and consume scarce resources.

Reduce embodied energy: This term refers to the sum total of energy that goes into a material right from sourcing raw material to its execution at site, or more seriously, finally being returned to nature.

By quantifying the data from all materials and construction energy spent, one can quantify the embodied energy of the building itself. The lesser the embodied energy, the more eco-friendly will the building be.

Explore nature: Building with nature is same as building with natural air, water, light and space. Maximizing them, not by artificial means using electricity but by passive means, would directly reduce resource consumption. This would minimise greenhouse gas emissions which is the major cause behind climate change.

Design effectively: Efficiency and effectiveness have no substitutes in architecture, for they pay back in daily comfort, save on electricity bills, create multi-functional spaces, assist in life cycle maintenance and many such others. Unfortunately, not everyone prioritises plan making, so a good plan should precede all other applications of eco-ideas.

Controlled costs: Cost has a complex relationship with sustainability, where the lowest cost may not be the most sustainable idea. Vitrified tiles are cheap, though they have high carbon footprint. Thatch roofs have lowest embodied energy but demand high maintenance. However, cost has much do with energy consumed and we need to take appropriate decisions for each context.

Perfect the innovations: With hundreds of ideas being introduced everyday, the construction sector is abuzz with excitement, but we do not know how many of them will perform well. Without giving the existing ideas time to err, correct, revise and evolve as a perfect solution, we discard them. Perfecting them is more important than innovating new ones.

We can list many more, however solutions are still hazy. Each one of us needs to explore options towards a better and safer future.

INSULATING OUR SHELTERS

The belief that walls and roofs should be solid for long lasting strength is a myth.

23bgp-green_G6M_23_2414967gCome summer and many of us pull out our old mud water pots and tell the kids its better to drink pot water than fridge water. Why? The mud insulates it from heat and the porous nature of its wall around permits micro ventilation, letting the water seep through. Termites could be enemies of our homes, but they are master architects building ant hills that maintain steady internal temperature. Once again, it is the principle of insulation and ventilation that play a role there, besides it being subterranean. Nature can showcase many more examples like bird nests. .

Traditional dwellings in rural areas were built with plain mud walls which insulates and local thatch roof which ventilates. Later on as materials changed, yet burnt brick walls and roof tiles continued to shelter the houses from heat and cold, though at a lesser degree compared to the vernacular style. This approach avoided non-local materials, structures were not monolithic and construction was not rock solid.

Blame game

Of late, our buildings are being designed differently. We appear to believe in solid walls with thick cement plastering to make it durable, layer of impervious paint in the name of protection, hard concrete roof to make the building strong and terrace finished with dense layers for water proofing. The high density materials all around let out heat conductivity warming up the inside, and sealed off interiors result in warm air trapped inside. Naturally, we blame the house for being a hot box and buy an air conditioner or ceiling fan. Imagine the days when neither of these existed.

The belief that rock solid materials last long is a misnomer. Construction timber lasts for centuries and so too a wall with lime finish. We often say they ‘breathe’, which is a principle behind their longevity.

Longer life

Seal them off, their life will reduce. The belief that walls and roofs should be solid for long lasting strength is another myth. The domes and vaults of century old monuments were neither monolith nor solid and they may last longer than all our modern buildings.

Majority of materials that we use today are machine made, with much higher density and lesser porosity than the natural or hand made materials that were used in the past. No wonder, they perform rather badly during the seasons.

Imagine designing with hollow materials like hollow clay blocks – they provide insulation thanks to the void inside, yet allow ventilation when built reverse with the openings connecting inside and outside.

Cavity wall

In case solid bricks have to used, they can be arranged as a cavity wall, either with full cavity or as in rat trap bond. Porous materials can be replaced by hollow core options, not only in the walls but also in the roof.

Filler roofs and slabs with light weight cement blocks as inserts are two easy-to-do examples, besides ventilated hollow roofs. Beyond the passive methods, only where need arises, one may consider mechanical methods towards indoor comforts.

We have re-discovered ways of designing for climate – now need to apply them.

Design should be localised

For the sake of insulation and ventilation, structures should be built in tune with the prevailing climatic conditions.

16bgp-greensens_16_2407907gAs the summer heat is receding and pre-monsoon showers are cooling our land, we can hear the sigh of relief everywhere. We can now be assured of burying our worries about buildings getting heated up, until next summer. We do not appear to realise that sweating out inside a building during summer, though mainly due to the season, is also partly due to the way we design and construct. Of course, summer can never be as pleasant as spring, but we can make our structures more liveable by adopting a few simple principles of design.

During the days of no electricity, our elders realised the two fundamentals for keeping the building cool – insulation and ventilation. Thick walls and roofs meant most of the heat being conducted dissipates within the material, resulting in the interiors being many degrees cooler compared to the outside. The same principle of insulation also applied during the cold winters, keeping the house warmer as well.

Desert architecture illustrates this phenomenon at best, where thick mud walls are common even today. To compliment it, the houses were provided with few small openings, minimising air movement and cross ventilation inside, considering the fact that the outside air too gets very hot there.

Contrast

In contrast, a house in Kerala would have thin clay tile roof, a material and roofing system not good for heat insulation at all, for insulation is not the challenge there. Instead, ample provisions are made to ensure air circulation – verandahs, perforated walls, many windows, internal courtyards, wall-top vents and such others. The heat which would get built up indoor would eventually get blown away by fresh cool air from outside.

Thus, by a judicious combination of the two — insulation and ventilation — the indoors were made bearable as per the appropriate needs of different regions. Today, our construction practices are getting so standardised, Chennai and Chandigarh may end up with similar buildings, despite varied climatic conditions. No wonder, there will be complaints about comforts.

After all, the modern systems dominated by frame construction, thin wall, painted surfaces, RCC roof and large windows is an averaged out approach to design and building. It may generally appear to fit into all places, but specifically suits no place.

The popularity of modern approach is based more on standardised functionality, dependence on electrical or mechanical gadgets, common PWD rules for public buildings across the country, ease of availability of non-local materials like steel, cement, tiles and such others. We cannot wish them away at this age when majority of local vernacular design methods have diluted, but can attempt working within these systems to suit the building better to local contexts.

Rediscovering and adapting the traditional wisdom has also been in vogue among many cities and architects. However the challenge appears to lie in working within the mainstream approach and make it address our climatic issues.

Willpower to live with nature

Our inaction towards eco-ideas comes from lack of priority and determination – both at the individual and collective levels.

09PP-greensense__0_2400108eWe all have heard people saying India is not a nation of voluntary compliance, hence knowledge of traffic rules or need for cleanliness does not deter us from violating rules or from littering. However, without that act of compliance, either voluntary or regulated, we cannot achieve our larger objectives. To that end, we cannot just have wishlists, but need to have a willpower.

We also know that mere awareness does not lead to action; as such we are ever ready with reasons to justify why we are not acting upon the known eco-friendly ideas. How many us who know about the resultant waste and eco-damage of mineral water bottles, plastic cups, polythene carry bags and such others have either fully stopped or minimised their usage? Without a survey, we may confidently say the number will not cross a handful. All of us will cite lack of time, un-economical pricing, busy daily routines, inaccessibility to a product, lack of peer support, fear of being ridiculed, losing interest and such others for not walking the talk.

Role model

Our inaction towards eco-ideas comes from lack of priority and willpower – both at the individual and collective levels. This is where mentioning Gandhiji becomes inevitable – the way he walked the talk and talked the walk is exemplary. Most of us are mentally not strong enough to convert our visions into actions.

We are conditioned by our contexts, consuming yet complaining; discarding gadgets claiming technological obsoleteness; buying what we can live without; criticising the current affairs knowing well how we are a party to it and publicly grumbling without private initiatives.

This is not to demean the people inclined to environmental consciousness doing their bit like avoiding plastics, minimal purchases, reducing electricity bill, minimising air travel, reusing products, taking public transport and such others. The Government has become increasingly pro-active with newer policies and their implementation.

Public institutions like CSE, TERI, IGBC, LBC and many others are also focused towards a low energy model for development. Yet, regional temperatures have been rising, climate change is getting accelerated and natural resource crunch is staring at us.

Low carbon footprint

We need a great willpower today if our tomorrows have to be secured – to accept personal discomforts to reduce the discomfort on the Earth; to moderate manufacturing; to live with lesser gadgets; to seek judiciously priced products with low carbon footprint; to shun luxury; to minimise global networking to reinvent the local; to attempt simple living with high thinking; to value biome higher than our biodata; to ignore monetary profiteering; to question surplus income and to earn enough to live with. Today, we need greater willpower than ever.

LIVING WITH SUMMER

Switching on the air conditioner is not the right solution as it only creates heat islands.

02bgp-greensens_02_2392591eThis summer season has been a much talked about one, at least for one reason. Which ever city one lives in or travels to, everyone gets to hear people discussing the rising temperatures. Architects and builders, especially those who claim to design eco-friendly houses, get frequent complaints from some or other house owners about how unbearable the indoor temperature has been. Most of us being impulsive in nature, start looking for an immediate answer as well.

From an ecological perspective, the rising summer temperatures and increasing financial affordability is prompting thousands of families in the tropical regions to buy air conditioners. A study published in National Academy of Sciences has placed air conditioners among the products poised for exponential growth in the coming years – a product already infamous for releasing Hydrofluorocarbons (HFC) which indirectly accelerates climate change. Besides, they transfer the indoor heat to outside, leading to heat island effects in business districts with large number of air conditioned buildings. In majority of cites in south India, the window ACs are used just for a few weeks in a year, questioning the idea of investment and benefit, even if it is at the individual levels.

It is a fact that no house can be built to perfectly suit all our local seasons of summer, winter and monsoon rains. If a house in coastal Kerala has to be designed to allow cross ventilation even during the rains, the same model may not be needed in Hyderabad or if built so, will end up filling the house with hot air during the summers, making it unlivable. Any study of traditional local architecture reveals that they were in general good for all seasons, but would perform badly in case of extreme conditions. While a non-stop flash shower with wind would make Bangalore buildings suffer, sudden spell of dry weather in an otherwise hot humid Chennai would create discomfort to the locals.

Unfortunately, by specifying 22 degree Celsius temperature, 50% humidity and hourly two cycles of air change, the habit-forming air conditioning creates a yearning in us for AC every time, diluting our inborn capacity to let the body get adjusted. All our ancestors lived all through the seasons, by appropriate food, clothing, indoor activities and bearing with the lead time required to get adjusted. Today, in the name of comfort, we are letting our lives get conditioned.

So, the challenge is two fold – firstly, to design the building most suited to all seasons, if not best suited to one season, and secondly, in the case of occasional extreme weather conditions in one season, let our human bodies get adjusted to the changing nature of heat and humidity.

Towards the first challenge, insulation and ventilation are among the major criteria, being the technical aspects of passive cooling, which can be further explored. However, for the second challenge of getting adjusted, it is only our wish and will power that can make a difference.