The typical asking rate per listing is in the $20's per square foot per year. The Lake Forest submarket is going through a a boost in rates. In the last 3 months, the median rate rose $3 per sqft per year. That's a 12% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Lake Forest region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 11 listings have been listed, which means new availabilities most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 9% of the available leases in the Lake Forest are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 1,730 sqft. Most properties in this area are around 2 stories. Most buildings in this area were built in 1981 and are Class B.
Not much of the real estate is used for commercial space, so it might be hard to find office space. Education is the dominant industry in this market. Most of the folk of Lake Forest work from home. Commuting close to 10 minutes a day is the norm for those who opt to reside in this part of town.