The Phillips Collection

Phillips House Renovation

Project at a Glance

Washington, DC


Bowie Gridley

Project Type


Project Overview

  • Structural steel installation in historic structure to support the rooftop mechanical penthouse addition
  • Managed sensitive logistics and safety adjacent to high-security embassies and the museum’s operational Sant Building
  • Protection of historic features and art installations during installation of new museum-grade HVAC systems

The Phillips Collection, America’s oldest modern art museum, was opened to the public in 1921 in the home of Duncan Phillips, an art collector and philanthropist. The 1897 Georgian Revival, three-story townhouse is located in Washington, D.C.’s Dupont Circle neighborhood and is now home to more than 4,000 works of modern and contemporary art.

The M/E/P systems of the original Phillips House hadn’t gone through a major restoration in over forty years. To preserve and protect the historic building and art, the project converted gallery spaces to a fully digitized temperature and humidity control system supported by new museum-grade HVAC systems. A vertical addition added a new rooftop penthouse, requiring the installation of structural steel below.

The project team’s creative strategy for constructing the vertical expansion and keeping the building weathertight involved shoring the existing roof structure, cutting it free from the building and lowering it four feet to allow new structural steel to be installed. Once the new vertical expansion was up, the old roof was removed from inside. The top floor below the new penthouse was also entirely reconfigured.

Throughout construction, a protection plan ensured that historic finishes, copper and millwork, including the museum’s permanent installation, Wolfgang Laib’s Wax Room—which houses a six-foot by seven-foot work of art comprised of 500 pounds of wax—were guarded against dust and temperature changes.