100 King William Street is an A-Grade office and retail accommodation with the major tenant Commonwealth Bank of Australia (CBA) South Australian Headquarters.

Quintessential Group of Companies (QGC) was a joint owner in 100 King William Street.

CBA exercised an option to remain in the building for an additional five years.

Mechanical upgrades were undertaken to bring the NABERS Base Building Energy rating from 3.5 to 4.5 Stars. Major tenancy refurbishments also took place on over 3,000sqm of office space. Lifts were refurbished and commissioned to improve tenant comfort.

The extensive building refurbishments and environmental upgrades resulted in enhanced secure rental income at the property.

QGC sold its interest.