The historic Arizona Biltmore Resort & Spa is celebrating its 80th birthday in grand fashion. Earlier this year the iconic resort opened the ultra-exclusive Ocatilla at Arizona Biltmore and this summer it got an even better present: The green light from the city of Phoenix for a $600-million renovation project. The Biltmore is the first major property rezoned under Phoenix's new Planned Unit Development ordinance, which fuses a developer's vision with community feedback. It was necessary because the Biltmore was originally zoned residential when it was built in 1929.

Architectural drawings are underway for the first phase of the massive project, which will see $300 million spent to build 300 new guestrooms, a new spa with underground parking and an expansion of the main pool. The architect of the new spa will be the Phoenix office of Gensler. Once the new facility opens, the old spa will close allowing for the expansion of the pool. The project should break ground next year, says General Manager Andrew Stegen, and take three to four years to complete. Once done, a new restaurant, more underground parking and 88 new rooms or condos will be added, which could take another five years.

The second $300 million is part of the 30-year plan to eventually demolish the current parking structure, move it all underground and add another 300 rooms. The 738-room resort could have 1,500 rooms when all is said and done.

“This master plan is very valuable for us now, or anybody in the future,” says Stegen, “because it gives us a roadmap of what we can do. And in all honesty, none of it has to be done, or all of it can be done. The economy will drive that.”

Ocatilla opened in February with 120 club rooms featuring custom furnishings, the private Ocatilla Pool and Ocatilla Executive Lounge offering exclusive amenities. The spacious 500-square-foot Club and Club Deluxe guestrooms are Frank Lloyd Wright-inspired with modern touches. Wright was a design consultant when the resort was built.

“It's more of a five-diamond experience,” Stegen says of the concierge-level building. “The design goal was to really have a sense of place, no matter where you are, you understand you're at the Arizona Biltmore.”

The Biltmore, part of Hilton's Waldorf=Astoria collection, is owned by Morgan Stanley and Pyramid Advisors.