On average, listings lease in the $10's per square foot per year. The Brent submarket is going through a a rise in rates. In the last 3 months, the median rate went up $17 per sqft per year.
In the last 90 days, 11 listings have been listed, which means spaces might be going fast. You'll want to be prepared to tour spaces as quick as possible. About 64% of the listings in the Brent are subleases, so you might be able to find a shorter term or below market rent. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,200 sqft. Most buildings in this area are close to 1 stories. Most buildings in this region were built in 1978 and are Class B.