Green is a phenomenon and not a formula. It is a concept more than a configuration. However, with more glass than the grass in built environment, “Green” seems to have remained a word rather than a colour. Building industry, with its share of 42%, is the highest consumer of world energy surpassing manufacturing as well as agriculture sector.
As architects we alter the landscape forever and we need to understand and be responsible for its far reaching consequence. For example recycling one aluminium can of coke can save energy equivalent of running television for nearly forty minutes, as aluminium’s embodied energy demands are 160 times than that of a sunburnt clay brick. Need we clad our buildings with aluminium panels in India?
In a day use building nearly ninety two percent of energy is spent in cooling (60%) and lighting (32%). This makes it quite logical for us to prioritize resource optimisation in these areas. A multi owner high-rise residential building has annual energy demands of (59.8KWH/sq. M) one and half times that of the single owner low rise building (40 KWH/sq. M). Entertainment centres guzzle three and a half times (135 KWH/ sq. M) while hotels and data centres are ten times energy intensive. But topping the list are the recently found shopping malls pegging energy needs at 565 KWH/sq.M. Needless is the debate whether after all these if they even measure up to the spontaneity, plurality and vitality of the traditional street bazaars.
It is also a fallacy to think that modern times imply more comfort. Electricity has been invented and applied since over two centuries but the world energy consumption of entire year of 1950, even after 150 years of electricity’s invention, is equivalent of today’s consumption of six weeks only. And yet it remains inaccessible to over 40% of world’s population.
As architects we are called to take six basic decisions and the sum total of which is wholesome architecture.
- Siting and location: This refers to orientation, exposure and impact of natural forces. In hot arid zones of India orienting building with its longer faces to North-South compared to East-West can reduce solar radiation and energy demands to nearly half.
- Form and Mass: This has potential to benefit from mutual shading and scaling. As a thumb rule energy demands can be reduced in a building in hot-arid zone up to ten percent by optimising on volumes. By adding a floor it gets reduced to about twenty percent. It gets nearly halved by attaching the building from sides as well as stacking floors above.
- Space organisation: As an effective environmental response, traditional buildings from hot arid regions have been compact, stacked, attached and interspersed with multiple courtyards to reduce heat gain. As against, Bungalows of the hot-humid zones have been extroverted with veranda like living spaces in the periphery to increase its transparency to breeze.
- Elements of Space making: This forms the essential syntax of the architecture and thereby it’s interactivity with external conditions. For example pavilion like structure with prominence of inclined roof form with absence of walls is the syntax of hot-humid climate. Conversely predominance of wall and subjugation of roof is the grammar of hot-arid climate zone.
- Material and Construction techniques: This is vital in setting forth the chemistry of building with external elements through its thermal coefficient, material properties and dynamics of its physics. If sunburnt clay block is taken as a unit of energy demand of material, cement is nearly ten times energy intensive, steel thirty times, PVC 120 times.
- Finishes and surface articulation: Although seemingly micro, the skin rendering turns out to be the first aspect of building to negotiate with environmental conditions. Dark versus white or very light colour rendering with glossier surface can create up to five degree temperature difference within through its high reflectance value.
Sustainability is a holistic concept involving culture, climate and construction. Green has to be our resolve rather than mere rendering.