Posted on:

600 Massachusetts Avenue, Washington DC

CORE architecture + design

Shared By

Samantha, CORE

Project Name

600 Massachusetts Avenue, Washington DC


600 Mass Ave


Project Status


Year Completed



400,000 sq. feet


Gould Property Company


  • Guy I. Martin
  • Ron Ngiam
  • Rod Sellers
  • Dean Hutchison
  • Smriti Nayak
  • Michael Borissow


  • Clark Construction
  • SK&A Structural Engineers
  • Girard Engineering
  • Gustafson Guthrie Nichol
  • Sustainable Design Consulting

Certifications and Designations



Project Description

600 Massachusetts Avenue (600 Mass) is a 400,000 square foot office building in Washington, DC. The building is designed to meet LEED Platinum requirements. Architecture/design firm CORE ( ) is working with the clients (Gould Property Company and Oxford Properties Group) to create a project that combines highly-efficient floor planning, clean aesthetics, forward-thinking amenities and green spaces that blur the line between what’s indoors and what’s outdoors.

CORE envisioned this building as a glass crystal embedded in a brick block–mediating between high-rise Massachusetts Avenue and historic Eye Street. CORE principal and lead designer I. Guy Martin, AIA, drew the first design sketches of the project for Kingdon Gould in 1981 so it’s immensely gratifying to see the final project under construction.

Starting as a 10-story glass office tower facing Massachusetts Avenue, the building cascades down towards Eye Street in a series of landscaped terraces that end in brick facades to reinforce the adjacent historic structures. The landscaped terraces not only provide outdoor space for the adjacent office spaces but also contribute to the building’s LEED Platinum rating.

The project’s design was subject to approval from the Historic preservation Review Board and the District of Columbia’s Office of Planning, as well as the City Council which had to approve an alley closing. The site has a complex geometry resulting from the L’Enfant plan’s angled avenues laid over a rectangular grid – Massachusetts Avenue is at an acute angle to Eye Street. The design takes advantage of this geometry to create a prominent corner element with views east down Massachusetts Avenue towards the Capitol.

To earn a LEED Platinum rating with the U.S. Green Building Council, the 600 Mass team addressed a spectrum of issues relating to sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, innovation in design and regional priority. The building’s numerous sustainable, integrated design elements include:
• The integrated design of the building envelope and mechanical system to ensure that the project will be energy efficient;
• Water-efficient landscaping and technologies, including the ability to capture and reuse 100% of rainwater, to minimize water use in the building, and substantially reduce water discharge from the building;
• A comprehensive recycling and waste management program to reduce landfill waste;
• Clean, filtered air to provide the highest indoor air quality to every floor; and
• Sourcing building materials and hiring a local construction team to reduce carbon emissions related to both transportation and ongoing energy consumption.

“The outdoor areas at 600 Mass will be spectacular,” said CORE principal and lead designer I. Guy Martin, AIA. “There are no other office buildings in Washington with this amount and quality of green space.” Five of 600 Mass’ 10 floors feature lushly-planted private balconies, and the rooftop offers a sophisticated, indoor/outdoor conference area.

600 Massachusetts was completed in December 2016.
Add A Project
Publish Your Projects Show off and upload images, text, and video of your work. We pick the very best for our project newsletters. Upload

Join the Discussion

Please read our Content Guidelines before posting

Close X