The Plaza Cos., a Peoria-based developer and manager of medical space and senior housing, plans to break ground in the coming months on two major medical campuses and is buying another. In all, the company plans to invest $40 million in the expansion into the West Valley.

The Plaza Cos. plans to begin construction Wednesday in Glendale on Arrowhead Professional Center III, a 9-acre medical campus. It will be anchored by Samaritan Surgicenters of Arizona, an outpatient surgery center operated jointly by Banner Health Systems and Triad Hospitals.

Eventually, the campus will have up to eight buildings. The project is being built between Bell Road and Union Hills Drive, and east of Loop 101.

Glendale and Peoria, two Phoenix suburbs, are about 10 miles northwest of downtown Phoenix.

The company is also planning a similar project in Avondale, called Rancho Santa Fe Center, with an investment of $14 million. The project will be anchored by an outpatient surgery center and will include medical office space. Construction could begin later this year. Avondale lies about 12 miles west of downtown Phoenix.

In May, the company plans to begin construction of a 35,000-sf biomedical research facility on its Plaza Del Rio campus in Peoria, an 18.5-acre medical campus at 94th Drive and Thunderbird Road. The company also purchased for $5 million the Palm Valley Medical Building, a 40,000-sf medical office building in the master planned community of Palm Valley in the Phoenix suburb of Goodyear.

The project is at the corner of McDowell and Litchfield Park roads. The company purchased the facility from Phoenix Memorial Hospital and Broad Land Development. Goodyear is a suburb of Phoenix that lies about 15 miles west of downtown Phoenix.

Much of the new housing in the Valley has begun to shift from the East Valley, where land is becoming scarce and only available further out, to the West Valley, both north and south.