Main part of my question was, how did you come up with this "astonishing" number of growth. The GDP and Economy grow at 5-7% percent for very high growth markets. That happens for about 2-3 decades and the growth starts to slow down. Unlike the US, India and China don't have the industrial and consumer base setup internally yet. And thus the 5-7%. But feeding such a large population means your GDP will start to have limitations in about 1-2 more decades, just like China has today. So even if we take an average of 5% growth (which is considered higher growth areas if you are above 5), over the next 35 years, 5*35 = 175% increase (quarter less than doubling the size). I can still stretch the numbers out and get to doubling the size. But three times won't happen. The world isn't the same like the 80's and the 90's. If today was 1990 and India was already where it is today as of 1990, I'd give you a 2.5 size expansion forecast. But the financial markets melt down and many other things have regulated almost every other industry that used to allow consumer and the builder, to freely move around and build wealth, which in turn runs the economy of a system.
I know TODAY that in Kernataka and Goa, there are many housing units that are available but not being purchased, like 1000 sqft Apartments inside the city built for people working in the city and all. Similarly, outside the city, bigger houses are available too and in quantity (please don't silly question me on this post as I was there last month).
Not yet on the same level as the Chinese, where they've built ghost cities, but in about a decade, you'll start to see a slow down (market correction). That happened in the US, in Russia, in Japan and is currently happening in China and everywhere else, India isn't an exception.
Note: this is a very serious subject and writing on issues like these, requires me to burn my time and do many calculations before I write stuff on here. My request, don't derail the topic. If you don't like what I wrote, sorry. No need to silly respond as I'll call Mods right away. Once in a while, a healthy debate should take place on here too.