Compared to the rest of the Bay Area market, the Larkspur submarket has higher rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 6 listings have come on the market, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 83% of the office spaces in the Larkspur 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 1,850 sqft. Most buildings in this market are close to 2 floors. Most buildings in this region were built in 1980 and are Class B.