Commonwealth Building (Portland, Oregon)

The Commonwealth Building is a 14-story, 194 ft (59 m) commercial office tower in Portland, Oregon, United States. Located at 421 SW 6th Avenue between Washington and Harvey Milk Streets, it was designed by architect Pietro Belluschi and built between 1944 and 1948. The building was originally known as the Equitable Building and is noted as one of the first glass box towers ever built, pioneering many modern features and predating the more famous Lever House in New York City.[4]

Equitable Building
Portland Historic Landmark[2]
Commonwealth (Equitable) Building in 2006.
Commonwealth Building (Portland, Oregon) is located in Portland, Oregon
Commonwealth Building (Portland, Oregon)
Location421 SW 6th Avenue
Portland, Oregon
Coordinates45°31′15″N 122°40′41″W / 45.520771°N 122.677997°W / 45.520771; -122.677997
Built1948; 76 years ago (1948)
ArchitectPietro Belluschi
Architectural styleInternational Style
NRHP reference No.76001584 [1]
Added to NRHPMarch 30, 1976[3]


1940s postcard of the building

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.[4] 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.[5]

The Commonwealth Building was added to the National Register of Historic Places (as the Equitable Building) in 1976.[3] In 1980, the American Society of Mechanical Engineers (ASME) designated the Commonwealth Building as a National Historic Mechanical Engineering Landmark.[6] In 1982, the building was the recipient of the Twenty-five Year Award, of the American Institute of Architects.[7] In 1993, Weston Investment Co. LLC bought the building for $1.9 million.[8] 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.[8][9] The building was sold again by Unico in 2013 for $41 million when Unico bought out Cigna.[10][11] Unico sold the tower to KBS in 2016 for $69 million.[12]



Designed by noted Oregon architect Pietro Belluschi, the 207,864-square-foot (19,311.2 m2) tower is of the International Style.[9] The 14-story, 194 ft (59 m)-tall glass box tower is constructed of sea-green glass and is sheathed in aluminum.[4][13]

Designations and awards


The building is listed on the National Register of Historic Places,[3] 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.[6]

See also



  1. ^ "National Register Information System". National Register of Historic Places. National Park Service. March 15, 2006.
  2. ^ Portland Historic Landmarks Commission (July 2010), Historic Landmarks -- Portland, Oregon (XLS), retrieved November 5, 2013.
  3. ^ a b c "Oregon National Register List" (PDF). Oregon Parks and Recreation Department. June 6, 2011. p. 32. Archived from the original (PDF) on June 9, 2011. Retrieved June 27, 2012.
  4. ^ a b c Ritz, Richard E. (November 27, 1983). "Portland's role in high-rise offices has gone up over years". The Sunday Oregonian. "Living" section, pp. 16–17.
  5. ^ Swing, William (February 28, 1965). "New Equitable Building Reflects Latest Stirrings In Architecture". The Oregonian.
  6. ^ a b Equitable Building Heat Pump (1948) from
  7. ^ "Twenty-Five Year Award Recipients". American Institute of Architects. Retrieved June 27, 2012.
  8. ^ a b Culverwell, Wendy (October 7, 2007). "New owner for the Commonwealth". Portland Business Journal. Retrieved October 17, 2013.
  9. ^ a b Culverwell, Wendy (October 16, 2013). "Historic Portland office building close to sale". Portland Business Journal. Retrieved October 17, 2013.
  10. ^ Culverwell, Wendy (October 29, 2013). "Commonwealth deal closes". Portland Business Journal. Retrieved October 30, 2013.
  11. ^ Njus, Elliot (November 25, 2013). "Downtown Portland office building, a pioneer in modern design, sold for $41 million". The Oregonian. Retrieved November 26, 2013.
  12. ^ Hammill, Luke (June 30, 2016). "Report: Office market races to add supply; Commonwealth Building sells for $69 million". The Oregonian/OregonLive. Retrieved July 1, 2016.
  13. ^ "Commonwealth Building". Buildings. Emporis GMBH. Archived from the original on May 14, 2015. Retrieved November 21, 2016.