The typical asking rate per listing is in the $20's per square foot per year. The Berwyn Heights region is going through a a rise in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 6% increase in rent.
Compared to the rest of the Washington D.C. market, the Berwyn Heights submarket has smaller rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 1 listings have been made available, which means new availabilities most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 1,000 sqft. Most properties in this market are around 3 floors. Most buildings in this market were built in 1991 and are Class B.