Compared to the rest of the Metropolitan Los Angeles market, the Glendora submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 7 listings have been posted online, which means new listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 14% of the office spaces in the Glendora are subleases, so you might be able to snag a great spot on a short term. 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 1,900 sqft. Most properties in this area are close to 2 stories. Most buildings in this area were built in 1985 and are Class B.