Most listings are in the $20's per square foot per year. The Portland submarket is experiencing a an increase in rates. In the last 3 months, the median rate went up $0 per sqft per year. That's a 0% increase in rent.
In the last 90 days, 52 listings have been posted online, so you'll want to check back regularly for new listings. About 2% of the available leases in the Portland 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 posted, 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 market are around 3 stories. Most buildings in this market were built in 1900 and are Class Class B.