Corcoran Gallery of Art

To evaluate the performance of the existing wall assemblies, WDP installed in-situ data acquisition instrumentation at key depths within the mass masonry walls to gather moisture and thermal data. This data was used to calibrate hygrothermal models as representative of the existing conditions. WDP evaluated proposed retrofits of the existing walls to improve thermal performance while balancing the vapor resistance behavior of the new materials in the mixed-humid climate of the mid-Atlantic region. The performance of the building envelope was coordinated with the design of the HVAC system, specifically in spaces that were designated for the National Gallery of Art, which required strict climate control. WDP performed hygrothermal analysis in accordance with ASHRAE 160-09, “Criteria for Moisture-Control Design Analysis in Buildings,” and designed wall assemblies that met the prescriptive thermal performance requirements of ASHRAE 90.1-2013. WDP also installed temperature, heat flux, and solar radiation sensors to evaluate the performance of the skylight assemblies and determine the value of restoring the existing assemblies versus replacing the components to meet the energy and performance goals of the building.

WDP investigated the existing conditions of the flat roof as well as water infiltration through a historic, sloped standing seam metal roof using water testing and infrared thermography. Based on the survey findings, WDP was tasked with preparing repair design documents for a roof replacement on a portion of this area where new equipment was being installed during a GWU renovation. Contract documents were created, including drawings and specifications for replacement of the existing built-up system with a self-adhered vapor barrier and 2-ply modified bitumen system that was tied into the existing roof system. Repair design documents also addressed repairs to the exterior brick masonry façade, installation of new skylight systems, and roof replacement on the Platt Addition.

• Field investigation of the exterior brick masonry
• Hygrothermal field instrumentation to assess as-built building envelope thermal performance
• Development of building envelope effective U-Factors for mechanical system design
• Brick masonry restoration design
• Roof system replacement design
• Skylight system replacement design