On average, listings lease in the $20's per square foot per year. The Renton submarket is going through a an increase in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 3% increase in rent.
Compared to the rest of the Seattle Metropolitan Area market, the Renton region has less expensive rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 18 listings have been made available, which means new 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 on the market, so finding a space for a small business might be tough.
Even though the median size is 4,990 sqft, there are still 0 listings below 2,000 sqft. Most buildings in this area are around 2 floors. Most buildings in this region were built in 1983 and are Class A.