On average, listings lease in the $20's per square foot per year. The Washington submarket is going through a a boost in rates. In the last 3 months, the median rate increased $26 per sqft per year.
In the last 90 days, 963 listings have come on the market, so you'll want to check back regularly for new listings. About 218% of the office spaces in the Washington 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 2,280 sqft. Most buildings in this market are close to 2 floors. Most buildings in this region were built in 1984 and are Class A.