On average, listings lease in the $10's per square foot per year. The Excelsior region is experiencing a a rise in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 7% increase in rent.
In the last 90 days, 25 listings have been made available, which means leases are probably going fast. You'll want to be prepared to make an offer immediately. About 16% of the listings in the Excelsior are subleases, so you might be able to find a shorter term or below market rent. 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 450 sqft. Most buildings in this market are around 2 floors. Most buildings in this market were built in 1985 and are Class A.