It's not hard to grasp the notion that buildings eat up a lot of energy. In fact, these blocks of wood, concrete and steel consume so much energy that they are responsible for more greenhouse gas emissions than the transportation sector, said Dan Geiger, executive director of the U.S. Green Building Council's northern California Chapter.

Geiger's talk kicked off a day of discussions about policies, novel materials and energy efficient designs at the Greentech Media's Green Building Summit in Menlo Park, Calif. last month.

A building outfitted with energy management sensors and software, as well as water-conserving features and other energy efficient amenities could not only reduce electricity bills, it also could improve workers' productivity and health.

The growing awareness that buildings are energy hogs presents business opportunities for construction materials companies and developers of software for designing buildings and managing energy consumption.

One panel featuring speakers such as Kevin Surace from Serious Materials and David Rosenberg from Hycrete discussed how startups could make money in the green building market and persuade customers in the construction industry to embrace new ideas.

Another panel debated the different approaches that can be taken to create a green building and educating the masses about what they can do to make their homes more energy efficient.

Is it more important to focus on the design or the use of novel materials? Do people realize they don't have to buy expensive solar panels to reduce their electricity bills? How do you set standards to gauge performances of green buildings?

The panels featured Matt Golden from Sustainable Spaces, Pat Bailey from Autodesk, Lynn Olechnowicz from Perkins + Will and Bruce King from Ecological Building Network.

The day ended with two Washington, D.C. insiders who doled out some advice about getting a share of the federal stimulus funds. Patrick Von Bargen from Quinn Gillespie & Associates and Michael Butler from Cascadia Capital also warned that companies could rely too much on government aid and not enough on building a business that would last and successful long after the stimulus money is gone.