The U.S. Bank Plaza, on the Capital Square in Madison, WI was designed by Bruce Graham of SOM in 1972, one year before the Arab oil embargo introduced Americans to energy security. The building’s three-story atriums with sloping un-insulated plate glass facing southwest made it impossible to control interior temperatures. The constant velocity HVAC system was noisy and unequipped to handle computer server rooms. Building energy use and operating costs were far above average.

Since we purchased the building in January 2008, we have focused on correcting the sources of tenant complaints. Inability to control temperature was a big issue. So was the stigma of the building’s profligate energy use. For 25 years we have actively focused on saving energy in our buildings. U.S. Bank Plaza presented a major problem-solving challenge that has become a pleasant obsession. The more success we have had in reducing energy and water use, the more we look for new initiatives to save. It is not merely to increase tenant comfort and save in operating expenses; it is the essence of being a responsible owner.

To date, we have completed the following projects.
• Replaced atria with high performance glass and full insulated roof decks.
• Installed two new 600-ton chillers and associated cooling tower.
• Replaced over 400 perimeter induction units with new low-pressure units.
• Constant volume system and associated reheats were converted to a VAV system.
• Converted pneumatic controls to DDC.
• Removed unnecessary heat pumps and fan coil units, which were wasting both water and energy.
• Installed “free cooling” heat exchanger to provide chilled water in the winter.
• Replaced oversized boiler pumps with properly sized pumps. Re-piped boiler and induction unit system for improved effectiveness and efficiency.
• Extended and modernized four traction elevators down to the parking levels and abandoned three hydraulic elevators.
• Installed carbon monoxide detection system on garage exhaust fans to reduce run-time.
• Performed comprehensive re-evaluation and adjustment of building standard operating procedures to reduce unnecessary run time and equipment operation.

We have cut our electricity and natural gas usage by roughly 35%. This equates to 2,500,000 KWh saved and 32,000 therms saved in one year. We have also cut our water use by 85% from 2006 total usage. These reductions in resource consumption have put us into the range to obtain an energy star rating through the US EPA. We have also begun the process to obtain a LEED EBOM rating through the USGBC.