Commonwealth Building (Portland, Oregon)

History

Construction on the building began in 1944, with it opening in 1948 as the Equitable Building. The building, which was built as the headquarters in Portland of the Equitable Savings and Loan Association, was originally intended to be 12 stories high but was later expanded to 14. It was the first tower to be sheathed in aluminum, the first to use double-glazed window panels, and was the first to be completely sealed and fully air-conditioned. In 1965, the building was renamed as the Commonwealth Building when the Equitable Center (now Unitus Plaza) opened, which was also designed by Pietro Belluschi.

The Commonwealth Building was added to the National Register of Historic Places (as the Equitable Building) in 1976. In 1980, the American Society of Mechanical Engineers (ASME) designated the Commonwealth Building as a National Historic Mechanical Engineering Landmark. In 1982, the building was the recipient of the Twenty-five Year Award, of the American Institute of Architects. In 1993, Weston Investment Co. LLC bought the building for $1.9 million. Unico Properties and Cigna Realty Investors bought the building in 2007 from Weston for $27 million, and spent $7 million more on renovations to the structure. The building was sold again by Unico in 2013 for $41 million when Unico bought out Cigna. Unico sold the tower to KBS in 2016 for $69 million. Commonwealth Property Owner LLC took possession on a $15,000,000 trust deed in July 2023, who then sold it for $6.5 million in December 2025.

Features

Designed by noted Oregon architect Pietro Belluschi, the 207864 ft2 tower is of the International Style. The 14-story, 194 ft-tall glass box tower is constructed of sea-green glass and is sheathed in aluminum.

Designations and awards

The building is listed on the National Register of Historic Places, and is also designated as a National Historic Mechanical Engineering Landmark by the ASME. The ASME History & Heritage Committee bestowed this landmark status for the specific feature: the first large commercial building in the United States to pioneer the use of heat pumps for heating and cooling.

References

References

1. Portland Historic Landmarks Commission. (July 2010). "Historic Landmarks -- Portland, Oregon".
2. {{NRISref. 2006a
3. Ritz, Richard E.. (November 27, 1983). "Portland's role in high-rise offices has gone up over years". [[The Oregonian.
4. Swing, William. (February 28, 1965). "New Equitable Building Reflects Latest Stirrings In Architecture". [[The Oregonian]].
5. (June 6, 2011). "Oregon National Register List". [[Oregon Parks and Recreation Department]].
6. [http://www.asme.org/Communities/History/Landmarks/46_Commonwealth_Building_Heat.cfm Equitable Building Heat Pump (1948)] from asme.org
7. "Twenty-Five Year Award Recipients". [[American Institute of Architects]].
8. Culverwell, Wendy. (October 7, 2007). "New owner for the Commonwealth". Portland Business Journal.
9. Culverwell, Wendy. (October 16, 2013). "Historic Portland office building close to sale". [[Portland Business Journal]].
10. Culverwell, Wendy. (October 29, 2013). "Commonwealth deal closes". Portland Business Journal.
11. Njus, Elliot. (November 25, 2013). "Downtown Portland office building, a pioneer in modern design, sold for $41 million". The Oregonian.
12. (June 30, 2016). "Report: Office market races to add supply; Commonwealth Building sells for $69 million". The Oregonian/OregonLive.
13. "PortlandMaps". City of Portland.
14. (31 December 2025). "Downtown Portland Commonwealth Building sold for $6.5M". Portland Business Journal.
15. "Commonwealth Building". Emporis GMBH.