The combined Potomac Annex and Navy Hill campus, located between the Department of State headquarters and the Kennedy Center in Washington, DC, is designated a historic district. The 19th-century campus is the site of the original Washington Observatory, which generated breakthrough research in the sciences of navigation and medicine. The campus contains the third of four sites historically designated as the American Meridian, along with the US Capitol Building, the White House, and the new Naval Observatory.

When the Department of State elected to consolidate multiple tenants from various leased annexes at the site, KCCT performed a comprehensive feasibility study consisting of four master plan options focused on the potential growth of new buildings and the adaptive re-use of the existing historic structures. KCCT gathered an extensive trove of information, including a physical survey of the site infrastructure, historic and archaeological research, existing conditions drawings, and program development scenarios. The feasibility study established the overall structure for the future master plan. 

Additionally, KCCT performed program verification and blocking and stacking plans. The four scenarios for the site master plan ranged in density from low-impact to high-impact renovation.

Subsequently, KCCT’s scope was expanded to include interior space planning, full-service renovation design, and construction administration services for four historically significant buildings, all with varying footprints, on their occupied campus. Future development scenarios propose sensitive infills and utilize grade changes to conceal density into hillsides so that height does not exceed the zoning of adjacent properties. Site upgrades designed to support the renovations and future expansion include a completely new PEPCO four-feed electrical distribution system to provide redundancy and reliability; telecommunications / distribution upgrades; archaeological and geotechnical monitoring; and localized site drainage mitigation design.

Repairs of the building facades included masonry cleaning and repointing to prevent water and air infiltration. Existing historic windows received replacement zinc weatherstripping to mitigate air leakage, and solar film was applied to window glazing. New telecommunications duct bank infrastructure was provided to connect all renovated buildings back to the main headquarters. 

All suite upgrades were designed to meet Department of State standards for a secure campus. As part of the multi-phased renovation on an active, occupied campus, KCCT developed the site utilization phasing plans for each renovation project. 

All buildings were equipped with a complete Building Automation System (BAS), which operated as individual control systems for efficiency and were connected to the facilities network campus-wide. The BAS included the fresh air makeup system, VRF heating and cooling, humidification and de-humidification systems, and lighting / shade controls.

The historic buildings contain ducted air systems via internal air-handlers at top and bottom levels. The VRF systems provide high levels of efficiency and climate control, while greatly minimizing the duct distribution sizes for the fresh air system. Both systems are controlled by the BAS both building- and campus-wide. Building commissioning for the systems began at the design development phase and extended to occupancy.

Indicative of the complex nature of a phased renovation in the heart of the District, this project necessitated coordination with multiple stakeholders. 

KCCT managed communication with all stakeholders from programming through construction, which involved not only user stakeholders, but federal approval agencies as well. They included:

• Department of State Real Property Management
• Department of State end user tenants
• General Services Administration
• Diplomatic Security
• National Capital Planning Commission
• Commission of Fine Arts
• DC Office of Historic Preservation
• District Department of Transportation
• DC Water and Sewer Authority
• DCRA Fire Marshall

Each of the fully renovated buildings achieved LEED Silver certification. Recycled content from the removal of several materials during the demolition phase minimized waste, and automated lighting shade controls minimized heat gain with the large windows were original to the building. KCCT applied an adaptive re-use of the building structure and building core, as well as the historic restoration of contributing spaces to minimize building waste. LED lighting and efficient plumbing fixtures were also utilized.