McKinstry Co., a Seattle-based mechanical engineering and construction concern with two Spokane offices, has been selected as the general contractor for a five-year $14.8 million project at Avista Corp.'s headquarters here to upgrade the building's heating, ventilating, and air-conditioning system, and to do electrical-system upgrades.

Laurine Jue, an Avista spokeswoman, says McKinstry's work will include completely removing and replacing the more than 50-year-old HVAC system in the main building, at 1411 E. Mission, as well as in the building's addition, which was completed in 1978. Together, the two structures have 157,000 square feet of floor space, she says. The current HVAC system in the five-story main building is outdated and inefficient, and is at risk of breaking down, Jue says.

Other planned work will include upgrades to the electrical and lighting systems, which are interconnected with the HVAC system, she says. The work also will include replacement of the windows in both the main structure and addition, and upgrades to the bathrooms to bring them into compliance with the Americans with Disabilities Act, Jue says.

The upgrades started this spring on the fifth floor of the main structure, and the work should be completed on both structures within five years, she says. Window replacement started in May, and that work is expected to be completed by mid-August, she says. River City Glass, of Spokane, has been sub-contracted by McKinstry to do the window-replacement work, she says.

The upgrades will save Avista about 1.4 million kilowatt-hours of electricity annually.

Last year, McKinstry upgraded the HVAC systems in Avista's auditorium and cafeteria building just north of the main building and in a large service building.