Reuters: New York’s Empire State Building is doing it, Chicago’s Willis Tower is about to start and many more landlords and companies are expected to undertake building retrofits to reduce energy costs. Spurred by steadily rising utility bills, the need to rein in costs in the recession, a host of government tax incentives and increasing awareness of carbon footprints, energy-saving building renovations are in vogue. “Things are thriving,” said Terry Singer, executive director of the …