On average, listings lease in the $20's per square foot per year. The Lansdowne submarket is experiencing a a boost in rates. In the last 3 months, the median rate increased $3 per sqft per year. That's a 10% rise in rent.
Compared to the rest of the Washington D.C. market, the Lansdowne region has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 1 listings have been made available, which means new listings are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 1,500 sqft. Most buildings in this market were built in 2007 and are Class A.