Greater Boston’s biotechnology real estate market is continuing its positive trend, with vacancy rates down across the market, according to a recent report.

The market, which consists of 16.3 million square feet of laboratory space, closed the two-quarter reporting period ended Sept. 30 with 13.1 percent vacancy, according to Richards Barry Joyce & Partners’ research report "bioSTATus – Winter 2011." The vacancy rate is down from 13.7 percent at the end of the last reporting period.

While the vacancy rates are low, the figures may not tell the whole story, as space is extremely limited in certain submarkets, including East Cambridge, Boston’s Longwood Medical Area and the Route 128 West submarket, according to RBJ.

Another significant trend for the region’s biotechnology real estate market is the impact of large, singular absorption events. In Boston and Cambridge, four major biotech construction projects commenced during 2011, totaling 1.7 million square feet of laboratory and office space. The projects make Boston one of the nation’s most active current development areas.