Most listings are in the $10's per square foot per year. The Dahlgren submarket is seeing a a rise in rates. In the last 3 months, the median rate rose $16 per sqft per year.
In the last 90 days, 8 listings have come on the market, which means listings might be going fast. You'll want to be prepared to make an offer immediately. About 25% of the available leases in the Dahlgren 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 posted, 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 area are close to 2 floors. Most buildings in this area were built in 1991 and are Class B.