San Francisco office rents jump 14 percent, on pace to surpass Manhattan – San Francisco Business TimesMega office leases such as Salesforce taking 714,000 square feet and LinkedIn grabbing 450,000 square feet as well as other tech leasing continue driving higher office rates in San Francisco. During the second quarter of this year, vacancy for San Francisco office space stayed flat at 7.2 percent while rental rates are up 14 percent compared with the same period last year, according to CBRE.