In the last 90 days, 6 listings have been posted online, which means spaces might be going fast. You'll want to be prepared to tour spaces as quick as possible. About 17% of the available leases in the San Anselmo are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around sqft. Most buildings in this region were built in 1962 and are Class B.