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 depreciated region.
In the last 90 days, 2 listings have been made available, which means office spaces are probably going fast. You'll want to be prepared to make an offer immediately. About 50% of the available leases in the Des Moines are subleases, so you might be able to snag a great spot on a short term. 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 1,670 sqft. Most buildings in this area are around 2 floors. Most buildings in this region were built in 1984 and are Class B.