The two-story building will be constructed on a 14-acre site near Interstate 294 and Interstate 290. The joint venture had acquired the slightly more than 14 acres and planned to construct a speculative building between 430,000 sf and 475,000 sf, says Phil Horstmann, president and CEO of Ascent. "Our original vision for the project was a purpose-building, speculative, multi-tenant data center," Horstmann says. Microsoft's lease rate was not disclosed but Jones Lang LaSalle had been marketing the building with an asking lease rate of $36 per sf, triple net.

The building was expected to have at least 200,000 sf with a raised floor and have 21-foot ceilings. Horstmann declined to say whether the facility constructed for Microsoft will have the same features.

"This facility will feature innovative designs to minimize energy consumption, such as airside economization which uses outside air for cooling, and other technologies which fully optimize the facility," Microsoft global foundation services corporate vice president Debra Chrapaty said in a statement. The building was expected to have 40 megawatts of power with the ability to expand to 60 megawatts and, with working on the plans for the building with Microsoft, "The capacity has grown," he says. The joint venture will also have its own power substation on the property.

Work began at the site in September. The building on the site was demolished and steel work is expected to begin on Monday, Horstmann says. The building is expected to be completed in the spring and open in April, according to a press release from Microsoft. The building will house "tens of thousands of servers providing information and web-based applications to Internet users worldwide," according to the press release.

Horstmann said Ascent will still construct a speculative data center but is not sure if it will be in the Chicagoland area. "That is our core business. We are currently working with clients in other cities as well as pursuing some other speculative data center developments," he says. Ascent currently has projects underway in eight markets and "works in 28 domestic US markets on an ongoing basis," Horstmann says.