On average, listings lease in the $30's per square foot per year. The Burien region is experiencing a a boost in rates. In the last 3 months, the median rate rose $13 per sqft per year. That's a 70% increase in rent.
Compared to the rest of the Seattle Metropolitan Area market, the Burien submarket has lower rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 2 listings have been listed, which means new availabilities might be 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.
The standard measurement for office space in this area is around 960 sqft. Most properties in this region are approximately 2 floors. Most buildings in this region were built in 1980 and are Class B.