Light industrial and warehouse-office space in the Washington area totals an estimated 30 million square feet. With the heaviest concentration in Prince George's and Howard counties, according to figures compiled in a recent market report made by Coldwell Banker, a commercial real estate brokerage firm.

"The size of the industrial data base in this area, based on verified research recently completed, is larger than anticipated for this predominantly white-collar area," said James B. O'Brien, vice president and resident manager of the downtown office of the large West Coast firm.

"And the industrial space market also tends to be spread out over many square miles, with about one-third in the District of Columbia, another third inside the Beltway and one-third in the outer suburbs," O'Brien added.

Additionally, the survey showed a vacancy factor of 9 per cent.

"While the vacancy factor is higher than expected in comparison to other cities," O'Brien added, "about one-third of the vacancies represent older, obsolete buildings, primarily in the District," O'Brien added. "If that amount of the vacant area is deducted, the vacancy factor - at 5 to 6 per cent - is more in line with other cities."

The survey also showed that this area tends to be basically an importer of almost all major products and commodities used here and exports relatively little. In recent years, as this metro area was growing, more of the industrial space use tended to be developed outside the District, particularly in the Washington-Baltimore corridor.

Migration of light industrial and warehouse space users declined in 1976, according to the report, which also noted that 224 industries have established operations in this area in the past seven years.