In fairness to the Department of Education, when they are building schools these days, they try to make an effort to make them energy efficient and as green as possible. Sadly, the builders rarely get it right because of the tendering process, (see idea 69.)
To add to the criteria of building schools, every new school will need to be built with whatever green solutions are available. This means things like proper rain water harvesting, energy from sustainable sources, A+ rated buildings, LED lighting, and so on. As a bare minimum, every new school needs to have the most up to date sustainable energy features.
Older schools also should benefit from sustainable projects. Any summer works scheme needs to have sustainability at the core of the project. Schools need to be upgraded to include green features.