On average, listings lease in the $30's per square foot per year. The Annandale region is going through a an increase in rates. In the last 3 months, the median rate went up $8 per sqft per year. That's a 27% increase in rent.
Compared to the rest of the Washington D.C. market, the Annandale submarket has greater rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 4 listings have been made available, which means leases 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 1,900 sqft. Most buildings in this area are close to 10 stories. Most buildings in this market were built in 1986 and are Class A.