NAPA -- Kaiser Permanente will soon undertake a $30 million renovation and expansion of its data center, adding 54,000 square feet to the remote building in Napa Valley Corporate Park.

Much of the $30 million price tag is attributed to equipment inside the building, according to a city Planning Commission report.

The expansion will include a 43,000-square-foot addition on the southern side of the building and an 11,600-square-foot addition on the northern side, according to the report. All told, the building will be approximately five acres worth of interior space, or about 213,600 square feet.

The building has long been used as a data facility, with previous owners including Citibank, MCI communications, Apple Computer, Electronic Data Systems and eventually Kaiser, which bought the building in 2006.

Construction will likely begin within the next month or so, said city planner Michael Allen. The Planning Commission approved the addition by a 5-0 vote in May.

Kaiser has other such IT and data facilities in Pleasanton and Corona.

The expansion at the Napa facility will include cooling towers, transformers, underground diesel tanks and other equipment, according to the report.

A total of 150 parking spaces will be removed, and about 51 employees work at the facility, according to the report.