Despite a trend toward going green, most U.S. offices get low or average grades for being environmentally friendly and few use renewable energy sources, according to workers in a poll released on Thursday.

Fewer than a third of office workers said their buildings are environmentally friendly, according to the poll of 6,486 office workers conducted for IBM Corp.

Slightly more than a third cited their buildings as average in terms of being environmentally friendly, and a third gave their buildings high scores, it found.

Fourteen percent said their buildings use renewable energy sources, while 60 percent said they do not, and 26 percent did not know or were unsure, it said.

While we're beginning to see some very good examples of green or energy efficient buildings around the world, around the country, there's still plenty of room for improvement, said Rich Lechner, IBM vice president, energy and environment.

Typically, half of the electricity going into commercial buildings is wasted, such as lights being left on, IBM said.

Roughly one-quarter of workers said their buildings adjust the office environment, such as lights and temperature, automatically, based on occupancy, the survey said.

Los Angeles scored highest for building efficiency among the 16 U.S. cities surveyed, with the most respondents saying their buildings automatically adjust lights and temperature and the most saying their buildings use renewable energy sources.

The IBM Smarter Buildings study, conducted by Survey Sampling International, surveyed 6,486 office workers online in 16 major U.S. cities on issues such as lights turning off automatically, presence of sensors that adjust lights and temperature, use of renewable energy sources, low-flow toilets and use of air-friendly products.

The survey was conducted from March 30 to April 12, and the overall statistical margin of error was plus or minus 2 percentage points.