It's commonly believed that when it comes to energy efficiency and buildings there's some low-hanging fruit -- but going after the rest costs a lot of money. Actually, that's not true, says C. David Myers, vice president for Johnson Controls and the firm's president for Building Efficiency.

Myers was in the spotlight Tuesday at the State of Green Business Forum in Chicago for a conversation with GreenBiz.com Senior Contributor Marc Gunther about perceptions, barriers and opportunities for energy efficiency in new and existing buildings.

The forum followed the release of the annual State of Green Business Report, which found that green building continues to be the buoyant element in the building industry. Energy efficiency retrofits in particular have seen growth as the projects produce financial benefits for the companies that pursue them as well as the firms that do the work.

Energy efficiency in buildings, batteries and power solution are core to business at Johnson Controls. Building efficiency alone is a $13 billion business for the company, which has paid consecutive dividends since 1887.

Capital budgets and financing continue to be barriers for many businesses contemplating energy efficiency upgrades -- but the obstacles can be hurdled with the help of energy service companies (ESCOs), Myers said.

In such arrangements, the firm that provides solutions performs an analysis for the client to assess the capacity of facilities, designs strategies and solutions for the client, partners with a bank to secure financing and is paid through the savings realized by efficiencies.

In the case of Johnson Controls, "we guarantee those savings, which enables the projects to go forward," said Myers. "To date, we have guaranteed and delivered more than $50 billion in savings."