Security Building, Commercial building in downtown Phoenix, United States

The Security Building is a 1928 Second Renaissance Revival building in downtown Phoenix, designed by Curlett & Beelman with regional contractors Edwards, Wildey and Dixon. Its reinforced concrete frame is clad in hand-molded brick with copper details; inside are marble floors and walls and brass elevator doors. The facade shows a central arched window with blue panes, stone medallions, a curved balcony and a stone balustrade.

Designed by architects Curlett and Beelman in 1928 and financed by prominent businessman Dwight B. Heard, the building was added to the National Register of Historic Places in 1985. Maricopa County acquired it in 2001 and undertook major restoration work beginning in 2005.

The name comes from the Security Improvement Company, headed by realtor Dwight B. Heard, which commissioned the building. It later served as headquarters for produce growers and law firms. Since 2001 it has belonged to Maricopa County and houses county offices; the ninth-floor penthouse added in 1958 was used by Arizona State University's Phoenix Urban Research Laboratory until May 2012.

The Security Building stands in downtown Phoenix at 32.92 metres tall, its tan and brown brick facade rising from a light stone ground floor with dark storefront glass and a recessed central entrance. It now houses Maricopa County offices, so the interior is a working government building rather than a public attraction; the marble floors, marble walls and brass elevator doors are seen by those with business there.

The ninth-floor penthouse was added in 1958 as the home of Walter R. Bimson, chairman of Valley National Bank of Arizona. From there until May 2012 the space housed the Arizona State University Phoenix Urban Research Laboratory. Look for the copper and hand-molded brickwork noted in accounts of the 1928 facade.