Asking rents for office space in San Francisco jumped 13.6 percent year over year to $34.30 per square foot in 2006 while they climbed 10.8 percent in Silicon Valley to $28.20

And here’s why Bay Area commercial rents are up.

Strong demand caused vacancy rates to fall to 10.6 percent in San Francisco and 11.2 percent in Silicon Valley, the lowest since the commercial real estate market crash after the dot-com meltdown. The Bay Area vacancy rate peaked in 2003 at 20.4 percent, rising from just 2.1 percent three years earlier at the height of the tech boom.

That’s wild! A 2.1% vacancy rate.