On average, listings lease in the $20's per square foot per year. The Lake Forest submarket is seeing a decline in rates. In the last 3 months, the median rate decreased $2 per sqft per year. That's a 5% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Lake Forest submarket has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 36 listings have come on the market, which means leases most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 3% of the available space in the Lake Forest are subleases, so you will probably need to consider the implications of signing a direct lease with the building. 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 1,780 sqft. Most buildings in this market are around 2 floors. Most buildings in this market were built in 1999 and are Class B.