On average, listings lease in the $20's per square foot per year. The Newington submarket is going through a a boost in rates. In the last 3 months, the median rate went up $22 per sqft per year.
Compared to the rest of the Washington D.C. market, the Newington region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 3 listings have been made available, which means office spaces most likley are going fast. You'll want to be prepared to make an offer immediately. About 200% of the available space in the Newington 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.
Even though the median size is 33,040 sqft, there are still 0 spaces below 2,000 sqft. Most buildings in this market are approximately 1 stories. Most buildings in this region were built in 1982 and are Class B.