UniSource Energy Corp. kicked off construction of the company�s new headquarters building on a two-acre downtown Tucson lot. The nine-story building will provide 170,000 sq ft of office space for more than 425 employees of Tucson Electric Power, the company�s principal subsidiary. The building also will include nearly 11,000 sq ft of ground-floor retail space as well as a conference center, meeting rooms and about 500 parking spaces. Developer and general contractor Ryan Cos. is expected to complete construction before the end of 2011.

The building has been designed by DAVIS and Swaim Associates from the ground up to conserve energy. Its rectangular footprint will minimize exposure to direct sunlight from the east and west, and an integrated shade structure will shield its western face. The exterior will be clad with high-efficiency glass, while the interior will feature energy-saving lights, HVAC units and other mechanical systems. A rainwater harvesting system will help ensure that all landscaping needs are met with recycled water, while a photovoltaic array will help power the building, including electric vehicle charging stations for employees and visitors.