As industrial continues its record run of net occupancy gains and shrinking availability, developers looking to build in some of the country’s most expensive urban markets are having a difficult time finding space. The solution? Some have taken to building upward.

Prologis, the world’s largest warehouse owner, will start construction on a three-story, 580k SF warehouse outside downtown Seattle next year, the first multistory warehouse in the country. The multilevel building will resemble two stacked warehouses, the Wall Street Journal reports, and will include loading docks on both the second and third floors, in addition to freight elevators for lighter-scale operations.

Though multistory warehouses of this kind are somewhat commonplace in Asian countries like Japan and Singapore where vacant land is difficult to find, the US has plenty of open space available in rural areas for industrial operators. But thanks to the growing demands of e-commerce, retailers are turning to urban markets to bring their services closer to customers, driving up rental rates.

Industrial markets continued to tighten in Q3 as US availability dropped 20 basis points, falling to 8.4% and marking the longest stretch of consecutive quarterly declines since 1989, according to CBRE. [WSJ]