On average, listings lease in the $20's per square foot per year. The Beaverton submarket is experiencing a a rise in rates. In the last 3 months, the median rate went up $5 per sqft per year. That's a 25% increase in rent.
Compared to the rest of the Greater Portland market, the Beaverton submarket has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 65 listings have been posted online, so you'll want to check back regularly for new listings. About 2% of the available space in the Beaverton 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 2,120 sqft. Most buildings in this region are around 1 floors. Most buildings in this market were built in 1987 and are Class A.