Most listings are in the $10's per square foot per year. The Cascades region is experiencing a a boost in rates. In the last 3 months, the median rate went up $16 per sqft per year.
Compared to the rest of the Washington D.C. market, the Cascades region has lower rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 3 listings have been listed, which means spaces most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 400% of the listings in the Cascades 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 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 1,000 sqft. Most buildings in this region are close to 3 stories. Most buildings in this region were built in 2002 and are Class B.