Today there are still some copyright issues, and convincing clients to take a responsibility on green and sustainable aspects of construction inside and outside remains difficult.
When it comes to getting at the truth, subjects like green and corporate social responsibility (CSR) rank right up there with asking a middle-aged man why he bought the sports car.
He reckons that leading his party into Germany's first ever Red-Green government lands him with a double responsibility, and he feels all the weight of it.