On average, listings lease in the $10's per square foot per year. The Des Moines submarket is seeing a decrease in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 17% decline in rent.
Compared to the rest of the Seattle Metropolitan Area market, the Des Moines region has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 2 listings have come on the market, which means spaces are probably leasing quickly. You'll want to be prepared to make an offer immediately. 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 1,670 sqft. Most buildings in this market are approximately 2 stories. Most buildings in this market were built in 1984 and are Class B.