A real estate downturn could cripple the growing co-working industry. : Some commercial real estate observers might be a little worked up about how office REITs might be affected by WeWork and its co-working brethren. Yet is that consternation really warranted? To be sure, WeWork—the giant of the nascent co-working sector—is gobbling up office space at a rapid clip around the country. Recent data from research firm CoStar Portfolio Strategy LLC shows WeWork has claimed more than 12.5 million sq. ft. across the U.S., with the New York City market representing 37 percent of its nationwide footprint.