Quantum Residential was founded in 1969 and is one of most tenured property management companies in the Pacific Northwest, managing over 6,000 units at 75+ properties in Washington and Oregon. Headquartered in Vancouver, Washington, Quantum is a third-party property management company that specializes in large multifamily properties.Quantum has been an Accredited Management Organization (AMO) with the Institute of Real Estate Management (IREM) since 1984. There are only 554 firms in the United States with this accreditation, making us one of the oldest and most experienced firms in this area.