For the buildings you own, of course you need to take a strategic approach, but you start with an assessment: what is the building energy intensity of each of the facilities you own? You start with the worst. Say you have 100 buildings. The worst are the ones you attack first, but you have to create the support to make those changes, such as a building revolving fund and shared savings programs.
The key is that throughout the government buildings you own, you have very understandable standards of performance that you want to see happen. That's your power as parliamentarians. You can set those standards and then let the bureaucracy implement them. That's what I would say.