On average, listings lease in the $30's per square foot per year. The Tigard submarket is going through a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 5% rise in rent.
Compared to the rest of the Greater Portland market, the Tigard region has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 25 listings have come on the market, which means spaces are probably leasing quickly. You'll want to be prepared to make an offer immediately. About 4% of the office spaces in the Tigard are subleases, so you will probably have to consider a longer term lease. 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 2,050 sqft. Most properties in this market are approximately 2 stories. Most buildings in this area were built in 1986 and are Class A.