I'd be surprised if the company in the building is the one who owns it - yes all Google, of course - but surely there's some tax avoidance possible ...
Google is just one of the tenants along with Food Network and Major League Baseball. They also own the building across the street, 111 Eighth Ave. Some other companies rent space in there too. Google has the cash, doesn't want to pay rent, and knows they are going to be there for a long time. Might as well buy the place. Not really a tax avoidance, although it certainly could be, but it's more like a cost avoidance. Estimated rent for 1.2m sqf is $6.1m/month for your typical office space in Chelsea. For a price of $2b, Google would get their money back in 30 years from collecting rent, assuming it never changes. I'm sure they are looking at closer to 15 years.
There are some corporate structures that seem better suited for owning real estate, like a Real Estate Investment Trust (REIT). Maybe there is a proxy "Google REIT" that is 100% owned by Google. Or some other proxy entity accounting stuff going on, such that Google is not "technically" the owner of the building, but a subsidiary with a different tax structure. I think that's what the parent meant.
> Maybe there is a proxy "Google REIT" that is 100% owned by Google.
There is no such thing under US law. A REIT must have at least 100 separate owners, and no group of 5 can own more than 50% in the second half of a given tax year.
They're only "in the market" if they are shopping for a new space. They just bought the same building they were in. That doesn't affect the commercial office space market.