One and Two Union Square

One and Two Union Square are among the most prestigious and inviting places to do business in Seattle. Award-winning design, dramatic views, splendid courtyards, superior office finishes, state-of-the-art systems and a management team dedicated to exceeding tenant expectations, all combine to make Union Square Seattle’s premier business address.



Located in the heart of Seattle at Sixth Avenue between Union and University Streets, Union Square is a vibrant and lively destination that offers a variety of retail, intimate outdoor spaces, casual and fine dining.



Union Square provides convenient access to I-5, I-90 (Bellevue) and 520 (Bellevue). Off-ramps are located at Seneca and Union, On-ramps at Spring and University.



The two buildings total roughly 1,806,000 SF with approximately 18,400 to 21,700 SF floor plates per floor. The two buildings are connected by a fireplace lobby and underground pedestrian concourse to the neighborhood.



The 1,100-stall parking garage offers tenants and visitors an unmatched convenience. Weekdays offer complimentary Valet parking and low evening and weekend rates of $7 are now available. Evenings start at 5pm-close, and weekends are Sat-Sun. Find out more at



The surrounding neighborhood is home to some of the best restaurants, hotels, retail and entertainment Seattle has to offer. 5th Avenue Theatre, Convention Center and Freeway Park, Pike Place Market, Seattle Art Museum, the Seattle Aquarium, ferry terminal and Olympic Sculpture Park are just a short walk away.



We are committed to maintaining buildings at the forefront of environmental design and operation. Both One and Two Union Square received LEED Platinum certification in 2015.

One Union

One Union Facts

  • 36 floors above ground
  • 657,531 Sq ft
  • Completed in 1981
  • Outdoor courtyard connecting One and Two Union Square
Two Union

Two Union Facts

  • 56 floors above ground
  • 1,132,554 sq ft
  • Completed in 1989
  • The building, at a height of 740 ft (230 m), is the third tallest skyscraper in the Seattle skyline.
  • The 20 x 30 foot US flag flies at about 300 feet higher than the top of the Space Needle.
  • Tip of the flag pole is 796’6” above the street and the 90-foot flag pole is 56’6” above the roof.
  • First in the world to use 19,000 lbs/in.2 concrete.


Energy Star TUS = 97, OUS = 97 – One and Two Union Square
LEED Certified 2009 – Certification of One and Two Union Square
LEED Platinum Certified 2015 – Certification of One and Two Union Square
BOMA Building of the Year 1999/2000 – Two Union Square
Puget Sound Blood Center 2011 – Community Service Award
Two Union featured in Architecture and Urbanism February 1991


Union Square stands as the Premier Seattle Office location, and is home to some of the most prominent financial institutions, law offices, real estate professionals, health care, and other professional firms. Union Square has many amenities right outside your door with no need to leave the building.

Click on an available floor to view its details and PDF.

One Union Square

Floor 1

RSF – 3,745

Available Now

Floorplan PDF >

Two Union
One Union
One Union Square
Floor RSF Availability Leasing PDF
3 7,542 Available Now View >
6 2,598 Available Now View >
8 1,017 Medical/Dental Space View >
17 997 Available Now View >
19 6,289 Available Now View >
22 18,489 Available 01/01/18 View >
25 2,952 / 6,587 Available Now View >
30 1,194 Available Now View >
Two Union Square
Floor RSF Availability Leasing PDF
1 1,348 Retail View >
16 7,799 Available Now View >
30 779 Available Now View >
37 2,447 Available Now View >

Leasing Contact

Mark Barbieri
Executive Vice President

Fax: 206-613-5301

Tim Holt
Senior Vice President

Union Square Retail & Restaurants

Just Downstairs

No need to leave the buildings to eat, shop, bank, grab a coffee or pick up your dry cleaning. These fine shops and restaurants are just downstairs:

In the Neighborhood

Down the Street

Union Square is located in the heart of downtown, walking distance to some of the best restaurants, hotels, retail and entertainment Seattle has to offer.


  • Hotels
  • Dining
  • Shopping
  • Museums
  • Entertainment

Show All / Show None

Crowne Plaza Four Seasons Grand Hyatt Hilton Hotel 1000 Hotel Vintage Park Inn At Harbor Steps Paramount Hotel Red Lion Sheraton W Hotel
Blueacre Seafood Urbane Hamanasu Wild Ginger Trace Cheesecake Factory Dragonfish Gordon Biersch Il Fornaio Loulay Kitchen and Bar Palomino Ruths Chris Tulio
Abercrombie Banana Republic Gap Macys Marios Niketown Nordstrom Old Navy> Pacific Place Urban Outfitters
Benham Photo Gallery Kimzey Miller SAM William Traver
5th Ave Theatre Act Theatre AMC Theater Benaroya Hall Century Link Field Gameworks Meridian 16 Paramount Safeco Field Showbox




Museums & Galleries


Arne Gillam Courtyard

If you are looking to escape the hustle and bustle of the city, the Arne Gillam Courtyard is the place to do so. Enjoy a sunny lunch break in the summer or a holiday stroll through the illuminated trees in the winter. Union Square offers this relaxing one acre of open space in the heart of the city.

Arne Gillam Courtyard Arne Gillam Courtyard

Conference Rooms

Union Square offers three conference rooms. In addition to our Union Square Boardroom, and our 3rd Floor Conference Room, we have a three-room conference center on the 51st Floor of Two Union Square, boasting spectacular views and contemporary amenities.

Schedule a Conference Room ›

51st Floor Conference Center 51st Floor Conference Center


Union Square gets LEED certification

SEATTLE — One Union Square and Two Union Square have been awarded LEED certification. Union Square has been working for more than two years to achieve the designation.

Arne Gillam of Washington Holdings, Union Square's landlord, said LEED certification is an important achievement in the current market. “Green buildings are the only viable option for many companies when choosing a new location.” The building owners have focused on energy use, recycling and low impact maintenance. New systems at One Union Square have reduced annual energy consumption by an average of 7.5 million kilowatt hours, a 40 percent reduction.


For things to do in and around Union Square and Seattle check out current and past issues of our quarterly newsletter (click on a thumbnail to view the PDF for that newsletter).

  1. Summer 2017
  2. Winter 2017
  3. Winter 2016
  4. Summer 2016
  5. Spring 2016
  6. Winter 2015



Seattle Office
600 University Street
Suite 2820
Seattle, Wa 98101


Tenant Services
7:30am-5:30pm M-F


Leasing Opportunities

Garage Office


Tim Holt | Senior Vice President/General Manager

Rick Mock | Director of Facilites

Aaron Blankers | Assistant Vice-President/Senior Property Manager

Mick Newell | Property Manager

Jim Smith | Director of Construction

Kendra Law | Senior Property Accountant

About Washington Holdings

Washington Holdings

Washington Holdings is a real estate investment firm based in Seattle. We purchase and develop commercial properties and acquire and originate debt investments secured by income properties. We primarily focus on properties in the major metropolitan areas in the Western United States. Our deep experience in the property and capital markets allows us to analyze investment opportunities efficiently and to act decisively when we believe an investment will generate attractive risk-adjusted returns.