Energy efficiency is the fastest and cheapest way to meet energy needs. Efficiency is an invisible resource -- one that is everywhere -- and yet often overlooked. According to McKinsey & Company, India could save $42 billion each year with enhanced efficiency; and the building sector could be a key source for those savings. Buildings already account for more than 30 percent of India's electricity consumption. Total building space in India will increase from 8 billion square meters in 2005 to 41 billion by 2030. Two-thirds of commercial and high-rise residential structures that will be standing in 2030 have yet to be built. Every building constructed without optimal efficiency represents a lost opportunity to lock in lower energy consumption and increased savings for decades.