Both Cushman & Wakefield and Grubb & Ellis show negative absorption between 315,000 square feet and 320,000 square feet for the quarter. According to the former, office vacancies stand at 15.3%, up from 12.3% a year ago, while direct asking rental rates average $2.55 a square foot, down from $2.73 a square foot in March 2008. The latter pegs vacancies even higher at 16.8% but also has rents higher at $2.65 a square foot. CBRE puts availabilities, which include sublease space and space scheduled to come vacant as well as currently vacant space, at 18.7%. The brokerage predicts availabilities will continue climbing for 18 months, peaking at 24.5% in mid 2011.

Grubb & Ellis researchers point out that some submarkets are holding up better than others. While Central County accounted for the majority of negative absorption, returning 349,483 square feet to the market, South County actually showed positive absorption of 49,920 square feet. Several small submarkets have notably low vacancy rates, led by the 470,225-square-foot Highway 56 Corridor with 0%. The largest of the strong-performing submarkets is the one-million-square-foot La Jolla area, with a 7.4% vacancy rate. At the other extreme, Rancho Bernardo, with four million square feet, shows vacancies above 35%, while National City, with less than 500,000 square feet, is more than 50% vacant. Downtown San Diego is 15.4% vacant.