Most listings are in the $10's per square foot per year. The Cascades submarket is going through a a boost in rates. In the last 3 months, the median rate increased $16 per sqft per year.
Compared to the rest of the Washington D.C. market, the Cascades submarket has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 3 listings have been made available, which means leases might be going fast. You'll want to be prepared to tour spaces as quick as possible. About 400% of the office spaces in the Cascades are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 approximately 3 stories. Most buildings in this region were built in 2002 and are Class B.