How do you design and build a structure that will use 63 percent less energy than a typical office building?

That’s the challenge a team of designers, engineers and contractors tackled to develop a new state office building meant to serve as a showcase for energy-efficient design concepts.

Located on the southeast corner of the state Capitol complex at 1375 E. Court Ave., the 44,500-square-foot building will house the Iowa Utilities Board and Office of Consumer Advocate – about 100 state employees – when it’s completed in December.

The V-shaped building, configured to maximize the amount of natural light reaching its windows, incorporates a long list of energy-efficient features, among them a geothermal heating and cooling system, rooftop photovoltaic cells to generate electricity and super-efficient precast concrete walls specially designed to eliminate thermal leaks.

“We are on target to achieve LEED Platinum,” said Carey Nagle, an architect with the Des Moines office of BNIM Architects, the Kansas City, Mo.-based firm that designed the building. Platinum is the highest level achievable under the Leadership in Energy and Environmental Design (LEED) program, which evaluates buildings’ energy efficiency and other eco-friendly qualities.

The building, which has a total construction cost of $9.8 million, will be among the first state facilities to incorporate a geothermal system, which will generate the lion’s share of the structure’s expected energy savings.

A series of bioswales built into the landscaping south of the building will conserve rainwater that drains from the site as well as from the adjoining streets.

Using occupancy sensors, the building’s energy management system will turn off all non-essential loads when offices aren’t in use. Light level monitoring will also be used to dim general space lighting to ensure the proper amount of light is provided in the work areas.

Workers will even receive automated e-mails suggesting times when they should open or close their windows to save energy. Photovoltaic cells mounted on the roof, along with a 20-kilowatt wind turbine that will be erected adjacent to the building, are expected to provide about 12.5 percent of the building’s electricity needs.

“We kind of emptied out the entire toolbox of energy-saving strategies for this building,” Nagle said.