The typical asking rate per listing is in the $10's per square foot per year. The Brentwood submarket is seeing a decline in rates. In the last 3 months, the median rate decreased $7 per sqft per year. That's a 28% decrease in rent.
In the last 90 days, 7 listings have been posted online, which means office spaces most likley are going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,100 sqft. Most properties in this region are approximately 3 floors. Most buildings in this market were built in 1965 and are Class B.