It's a familiar story in image-conscious Las Vegas: When something reaches middle age, it gets ditched for something newer. In the case of the 40-year-old City Hall, not only did Las Vegas outgrow the facility, but the building also needed at least $1.5 million in energy-related retrofits. So the city's 600 employees left the old facility and moved into a swanky new $146.2-million, seven-story building in February, just around the corner from the old one.

Fortunately, Las Vegas is also famous for reinvention, meaning the vacant building won't stay empty for long. Internet retail giant signed a 15-year, $18-million lease to occupy the city's former digs in December 2010 and is currently spending $43.5 million to update the 11-story building completed by Del E. Webb in 1973. The Penta Building Group, Las Vegas, is the design-build general contractor, with KMD, San Francisco, as architect and Las Vegas-based Carpenter Sellers Del Gatto as associate architect. Chicago-based Jones Lang LaSalle is the construction manager.

Renovation work began at the downtown site in March 2012 amid high expectations that the project would lead to a renaissance of new investment in the city's troubled downtown core. "The Zappos deal will bring at least 1,200 total jobs to the city for a $336.6-million economic impact when its doors open," says Las Vegas Mayor Carolyn G. Goodman.

The project is expected to generate $126.3 million in employee wages and benefits annually, and increase the annual property tax in the area by $395,900, according to John Restrepo, principal of RCG Economics, which performed a project impact study for the city.

The project is currently under budget and scheduled to finish on Sept. 1.

Zappos is presently headquartered at Green Valley Corporate Center in Henderson, Nev., about 17 miles southeast from its future campus. The 14-year-old company was acquired by in 2009 for $1.2 billion in stock.

Strong Bones

The 139-ft-tall, football-shaped former City Hall tower and three-story circular low-rise are being completely gutted and retrofitted with modern electrical and mechanical systems. J&S Mechanical Contractors, Draper, Utah, and Dynaelectric Nevada, a unit of EMCOR Group, Norwalk, Conn., are the design-build subcontractors, with JBA Consulting Engineers, Las Vegas, as mechanical, electrical and plumbing engineer.

The 8,827-sq-ft central plant is getting four new 3,000-MBh boilers, two 250-ton chillers and modern controls. The electrical systems are being revamped to accommodate a 5,470-sq-ft, 36-cabinet computer server room in the basement to handle the influx of 5,000 customer calls a day and thousands of emails. The building will use 120-V electrical lines hung overhead with J-hooks for maximum floor plan flexibility.

The 276,500-sq-ft complex will also receive a new roof, carpet, fixtures and paint.