"They dramatically updated their space to create a lot more exposed area to daylight," Kreuger tells GlobeSt.com. "They did some interesting things with lighting controls to go green and improve daylight within their space."

The Silver LEED-certified project installed energy-efficient Lutron eco-system lighting controls into VOA's space. Renovations also added two video conference rooms and a staircase to connect the company's two floors in the building. The Chicago-based company has been housed in the building since 1990, and moved from the 13th and 14th floor into swing space on the seventh floor in early 2008 to allow for the renovations.

In July 2007, the company expanded its space in the building by 15,000 square feet. At the time, asking lease rates were around $30 per square foot gross. Kreuger declined to comment on current asking lease rates in the building.

The building is owned by the Hamilton Partners, which acquired the property in 2005 for a reported $53 million. The 388,000-square-foot, 18-story tower is currently about 84% occupied, according to the company's Web site. Designed by Daniel Burnham, the building was constructed in 1902 in the Central Loop submarket, where asking lease rates average around $38 per square foot gross, and the overall occupancy rate is around 88%, according to Cushman & Wakefield market research.