Crescent Real Estate Holdings is moving forward to build a 30-story, 600,000-square-foot 6 Houston Center office building to help fill a void: Houston Class AA's occupancy rate is at more than 96 percent, company officials state.

The new office building is to be located in the east side of the city's central business district with Rusk, Caroline, Walker and San Jacinto streets as boundaries. The 35-foot-tall lobby will face Rusk Street.

Designed by HKS Architects, the project is a pre-certified LEED Gold structure offering 10-foot and 12-foot ceilings on upper-level floors. Proposed for the the 10th floor are a concierge desk, rooftop garden, fitness center and conference center exclusive to building tenants. Occupants will have access to a nine-level garage.

The building will also feature a coffee bar, customer lounge andsecure bike storage. A 15-foot-tall glass skybridge connects to 1 Houston Center.

Crescent officials expect to secure building permits and select a general contractor in March and anticipate breaking ground by mid-summer of this year.

Crescent is the developer and owner of several other Houston projects, including Houston Center, Post Oak Central and Greenway Plaza.