Most listings are in the $10's per square foot per year. The Lake Forest submarket is experiencing a decrease in rates. In the last 3 months, the median rate decreased $9 per sqft per year. That's a 33% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Lake Forest region has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 29 listings have been posted online, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,610 sqft. Most properties in this area are approximately 2 floors. Most buildings in this market were built in 1999 and are Class B.