On average, listings lease in the $30's per square foot per year. The Diamond Bar submarket is seeing a decline in rates. In the last 3 months, the median rate decreased $1 per sqft per year. That's a 2% decline in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Diamond Bar submarket has higher rates, and you'll need to pay a premium to be in this hot region.
In the last 90 days, 15 listings have been posted online, which means listings 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 1,650 sqft. Most properties in this market are around 2 floors. Most buildings in this region were built in 1988 and are Class B.