Most listings are in the $50's per square foot per year. The Bethesda region is experiencing a decrease in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 2% decline in rent.
Compared to the rest of the Washington D.C. market, the Bethesda submarket has greater rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 29 listings have come on the market, which means new listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 3% of the available space in the Bethesda are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,400 sqft. Most buildings in this area are close to 10 stories. Most buildings in this market were built in 1976 and are Class A.