IRVINE, CA—The Quintana Office Campus, which traded in August, will be renovated to attract additional tenants.

Now that the year has hit its halfway mark and the second-quarter data have come in, what's the state of—and prospects for—the nation's top 10 markets with the most space under construction?

PHOENIX—Hines recently completed a 60,000-square-foot long-term lease for Jones, Skelton & Hochuli at its downtown Renaissance Square.

CHICAGO—ConAgra just became the latest suburban firm to make the jump from suburb to city, and experts say the trend could accelerate once the CBD's new office towers start opening next year.