BOULDER, CO—Energy efficiency retrofits on commercial buildings domestically and internationally will total nearly $1 trillion between now and 2023, says Navigant Research, headquartered here. Regulations mandating such retrofits are one factor behind the estimated $959 billion in expenditures, but by no means the only one, says Navigant.

“While government mandates play an important part in driving this growth, many retrofit projects are being undertaken on a voluntary basis, as corporate sustainability initiatives spread,” says Eric Bloom, principal research analyst with Navigant. That being said, Navigant cites some of the motives that governments may have to require greater efficiency.

“Many countries, especially the developing nations in Southeast Asia and other regions, are looking to shore up their energy supply structure and identify measures to address energy demand issues,” according to the report. “The increasing deployment of energy efficiency retrofits for commercial and public buildings provides an important pathway for increasing energy security, reducing – or even decreasing – energy demand, reducing GHG emissions, and reducing demand for new energy production and distribution facilities.”

That being said, the report points out that energy efficiency retrofits can also be used by commercial building owners and tenants to support greening and green marketing efforts. That’s the case even as a report from the United Nations Environmental Programme this past February found that the financial community needs more information to price the risks and rewards of retrofits.

Navigant is forecasting that global revenue for energy efficiency commercial building retrofits will grow from $68.2 billion in 2014 to $127.5 billion in 2023. The global market is expected to grow by 7% annually for the next nine years, led by Asia-Pacific.

The payback periods for energy efficiency retrofit projects are slowly decreasing, according to the report, but they remain a critical factor for most building owners and managers. Tolerance for longer payback periods varies both by region and by building owner category. Only 15% of all energy efficiency retrofits are initiated with increased energy efficiency as the primary motivator, with the remaining 85% undertaken for a variety of reasons, the report concludes.

Given the impact that existing buildings have on energy infrastructure, it’s not surprising that they’d be a foal point, whether by lawmakers or ownership. “On a global scale, buildings (both residential and commercial) account for 35% to 40% of total final energy consumption,” according to Navigant. “Commercial buildings, for example, consume a considerable amount of energy related to HVAC, lighting, water heating and various other building functions.”