If you’re wondering just how much of an effect Amazon‘s HQ2 could have on real estate in the city it chooses, take a look at its presence is in the Seattle metropolitan area. There, the company currently occupies 13.6 million square feet, or the equivalent of five Empire State Buildings.

That’s based on a new report published by BuildZoom, an online marketplace for contractors and home builders. According to the report, Amazon’s office footprint in Seattle spans 13.6 million square feet across 45 structures in downtown Seattle, Bellevue, Queen Anne and South Lake Union. By way of comparison, the Empire State Building has 2.8 million.

That’s much bigger than the 8.1 million square feet previously disclosed by Amazon. BuildZoom, which looked into publicly available building permits and other media reports for the estimate, said the discrepancy likely comes from the buildings located outside of downtown Seattle (Bellevue and Queen Anne) and future leases and structures currently in development.

The scale of Amazon’s headquarters in Seattle gives a clue to what the city that wins Amazon’s HQ2 bid will have to expect. Currently, 238 proposals from 54 different regions are waiting for Amazon to announce the winner for HQ2 early next year. Amazon said it plans to invest over $5 billion in HQ2 and create over 50,000 new jobs.

“A campus of this magnitude will not be easy for any city to accommodate except for the very largest,” BuildZoom’s Chief Economist Dr. Issi Romem wrote in the report.

Romem pointed out that Amazon will likely help fill office space in the city that wins the HQ2 bid. But at the same time, it could create problems by increasing office rent and pushing out existing tenants, he wrote.

“Amazon will likely reduce vacancy rates, crowd out other tenants, and drive up office rents, especially in the short run. In the longer run, Amazon will expand the office supply and, more generally, help deepen the talent pool,” Romem wrote.

Here’s an infographic by BuildZoom showing how Amazon’s footprint in downtown Seattle has changed over the years: