Most listings are in the $20's per square foot per year. The Milwaukie region is experiencing a a rise in rates. In the last 3 months, the median rate increased $11 per sqft per year. That's a 74% rise in rent.
Compared to the rest of the Greater Portland market, the Milwaukie region has smaller rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 1 listings have come on the market, which means listings most likley are 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 area are around 2 floors. Most buildings in this region were built in 1988 and are Class B.