The 'Great Stupa' at Sanchi is the oldest stone structure in India and was originally commissioned by the emperor Ashoka the Great in the 200 BC. Its nucleus was a simple hemispherical brick structure built over the relics of the Buddha. This structure has been standing for 2200 years now. How many of our buildings can achieve the same now? Should we try to achieve this? Will that be a sustainable solution?


Source: By Marc Shandro (Flickr) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
 

Air conditioners are rated for their energy consumption performance by a star rating. A five star rated air-conditioner, saves a lot of energy during the use phase of the product’s lifecycle. That is more sustainable than a 1 star rated air-conditioner. But how does one access when one should go for replacement of an old  air-conditioner with a new one? Should it be after 5 years or 10 years? How does one find that out? Will not discarding the current air-conditioner and going for a new one be considered unsustainable behaviour? How in that case does one compute the right age and reason for discarding or retaining the air-conditioner? Can one design the air-conditioner to be of some alternate use at the end-of-life rather than sending it as scrap into the dump yard. These are searching questions that one must raise in the design of product or product systems that are sustainable.




To give one more example, a paper crate can be used to transport fruits and vegetables as also alternately a plastic crate? Which one amongst these is a more sustainable solution? The use of Plastic may be polluting but is paper free of such effects? What is the effect of printing and using staples on paper in terms of its recyclability?




Source: By PatHaugen contacted by email at pathaugen@gmail.com or the website http://www.pathaugen.com/ [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons


A simple glass vs plastic comparison:
For a water bottle that contain 355 ml,
• An empty glass bottle weighs 265 g.
• An empty PET bottle weighs 30 g.




One thousand PET bottles represent 11.7 kg of GHG emissions for manufacture. Once filled, they collectively weigh 385 kg. When shipped 1000 km this equals21.83 kg of CO₂. This adds up to 33.5 kg (11.7 kg + 21.83 kg) of CO₂ for every 1000 PET bottles shipped 1000 km. This compares with 224.9 kg of CO₂ for 1000 glass bottles shipped 1000 miles!




The next few sections of this course let us disuss the various definitions and parameters which will help the reader to answer the above raised questions regarding sustainability.