Compared to the rest of the Metropolitan Los Angeles market, the Tustin submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 35 listings have been listed, which means leases 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 1,690 sqft. Most properties in this area are close to 2 stories. Most buildings in this region were built in 1982 and are Class B.