The amount of vacant office space on Oahu grew last year after two years of shrinkage.

The vacancy rise was modest — roughly amounting to the equivalent of an eight-story building. But it represented a setback for a part of the local commercial real estate market that had seen a decline in vacant space in 2012 and 2013 amid general economic growth. Before 2012 the economic downturn produced five consecutive years of rising office vacancy.

"The office market appears to be taking two steps forward and one step back," said the report from commercial real estate firm Colliers International released for publication Friday. "While the fundamentals indicate that vacancy rates should have begun to decline over the past few years, this has not consistently happened."

Despite the recent market weakness, Colliers said the average monthly base rental rate per square foot rose to $1.64 last year from $1.55 the year before.

Colliers said office leasing agents are getting increased interest from tenants seeking to expand, which along with continued economic growth should lead to lower office vacancies this year.

The company predicts that almost 100,000 square feet of space will be filled to bring the vacancy rate below 13 percent by midyear.

At the end of last year, the vacancy rate was 13.15 percent. That was up about one percentage point from 12.24 percent at the end of 2013.

Last year’s 13.15 percent rate represented about 2 million square feet of empty space out of 14.9 million square feet islandwide. About 78,000 square feet more vacant space was added last year after declines of about 100,000 square feet in each of the two previous years.

Colliers said the negative results last year were largely driven by relocations and downsizing of a few big office users partially offset by a couple of company expansions.

One major move was made by the National Oceanic and Atmospheric Administration, which consolidated staff to federal land at Ford Island from office buildings largely along the Kapiolani Boulevard corridor. Colliers also noted that the state Office of Hawaiian Affairs and Queen Emma Land Co. moved out of leased offices into space they own.

Among firms that downsized were Parsons Brinckerhoff and Sandwich Isles Communications, Colliers said.

On the growth side, Hono­lulu Home­Loans and Premier Business Solutions made expansion moves that filled nearly 30,000 square feet of office space, the report said.

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