The Philadelphia Department of Public Property (DPP) required highly-detailed surveying and 3D Laser Scanning Services for the historic Philadelphia City Hall to support condition assessment and documentation. Colliers Engineering & Design was retained to provide accurate color laser scanning data (LiDAR) of all exterior surfaces on the four main exterior facades, the main courtyard, and the rooftop exteriors. The combination of highly-detailed 3D Laser Scanning data and HDR photography provided the client with an invaluable tool to assess and make measurements for the existing conditions of stone work and structural elements.

Terrestrial Laser Scanners were utilized to gather all LiDAR and photographic data. The registered database of all scans completed for each phase of the project was geo-referenced to the primary control network coordinates provided by the City. The application of 3D Laser Scanning significantly reduced the period of the project and limited the impact on day-to-day operations at City Hall.