Compared to the rest of the Seattle Metropolitan Area market, the Burien region has less expensive rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 2 listings have been listed, which means office spaces are probably going fast. You'll want to be prepared to make an offer immediately. About 100% of the listings in the Burien are subleases, so you might be able to sign a shorter term by taking over a previous 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 1,280 sqft. Most buildings in this region are around 1 stories. Most buildings in this area were built in 1980 and are Class B.