Façade Survey with Laser Scanning Technology

Task

The task consisted of the restoration of an old industrial building, listed for preservation, in Magdeburg, Germany. 3D laser scanning was used for the survey. The structure, surfaces, dimensions and the geometry of three façades were being determined by laser scanning technology. Data analysis and interpretation were performed in PointCab and Geograf on a 1:50 scale.

    

Goal

Within the context of the buildings’ renovation and conversion, the goal is to build 22 lofts in the group of buildings. Renovating the buildings while preserving the historic substance has been a major task to be realized, which requires highly detailed and dimensionally accurate façade plans. Because of limited available space, the survey of the façade, which reaches 55 feet in height, could only be achieved through the use of a non-contact method. The prerequisite of detailed plans that serve as the basis for planning decisions is highly accurate as-built documentation.
Consequently, 3D laser scanning is becoming more and more an integral part when it comes to architecture and the protection of historic buildings and monuments. Furthermore, this method allows accurate area and cost calculations.

Realization

A total of 1,720 meters was surveyed—469 meters of the façade on the yard side, 442 meters on the east side, 810 meters on the side of the street. The smallest of the three façades is the façade on the east side, which proved to be a huge challenge because of its specific structure and geometry.
The survey, however, was carried out by only one engineer within a time frame of approximately 5 hours. As a result, significant savings in time, effort and cost involved in external work were achieved.

Analysis

All orthophotos were automatically created by the software PointCab by Laserscanning Europe from the laser scanning results in less than one hour.
Thanks to the PointCab images, the data collected could be used in a CAD system in approximately 30 hours. The results created are detailed layers and represent structured digital 2D plans of the façades, which are capable of visualizing the complex structure and geometry of the east façade. Furthermore, the client was provided with a free and easy-to-use point cloud viewer allowing the client to measure dimensions and proportions at a later point in time. There is a considerable reduction in planning time of the renovation and conversion works because views and sections of the 3D CAD model can now be used to efficiently meet specific demands of the client.