The typical asking rate per listing is in the $20's per square foot per year. The Brea submarket is experiencing a decline in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 10% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Brea region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 17 listings have come on the market, which means new availabilities most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 6% of the office spaces in the Brea 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.
Even though the median size is 6,070 sqft, there are still 0 listings below 2,000 sqft. Most properties in this area are close to 2 stories. Most buildings in this region were built in 1985 and are Class B.