Capitol Plaza Green Roof Addition

SK&A’s Repair & Restoration Division evaluated the adequacy of an 11-story office building’s roof structure to accommodate a green roof retrofit.  Built atop of a two-level parking garage, the building is approximately 153,344 SF including plazas, while the new green roofs account for 11,000 SF.  Structural evaluation included providing detailed structural analytical computations to evaluate the roof’s capability of supporting the green roof addition plus required service loading, such as snow load, live load and snow drifts. Additionally, certain areas of the main roof and penthouse roof frame were evaluated to receive solar equipment. SK&A determined that the roofs were adequately designed to support the anticipated loads from the green vegetative roofing assembly in addition to the multiple load combination. 

SK&A categorized the scope of work needed for the green roof addition and provided roof plan view drawings for initial cost estimates. Following the survey, SK&A prepared plans and specifications for inclusion in the application package for DDOE’s Green Roof Rebate for Targeted Large Retrofit Program, designed and specified the green vegetative roofing system, provided structural waterproofing details to integrate the system application with those of the manufacturer standard details and prepared selective demolition and removal of the existing roofing assembly only to the extent to accommodate the new application.