Laser scanning revolutionises architecture and the building industry
The wealth of analysis options makes 3D laser scanning very attractive when conducting detailed surveys of even the most complex building structures. Thanks to modern hardware and software solutions, the cost of scanning services has now fallen sufficiently to be competitive with manual measurement methods.
Coventry, February, 2013 – FARO Technologies, Inc. (NASDAQ: FARO): Detailed and reliable measurement data is particularly necessary in the measuring and planning phase of buildings and in building refurbishments – for both interior spaces and outdoor facilities. Because accuracy and error-free measuring are the basis for all sound planning and inventory surveys, the simple processing of 2D views is now no longer enough in most cases.
Examples from the architects at "laser scanning architecture" show how planning errors can be avoided and the efficiency of projects increased with the fully automatic Focus3D laser scanner from Faro. The office in Hannover was assigned the task of checking the existing drawings of an office building. These were to be compared with the as-built situation. Measurements of the shell of the administrative building to be renovated were taken with the FARO Focus3D laser scanner. Architect Johannes Rechenbach made 30 individual scans in just five hours, comprehensively documenting 2,800 square metres of façade surfaces and 1,500 square metres of floor space in 3D.
Architectural firms predominantly work in 2D these days. As a result, distortion-free 2D presentation is essential as a basis for planning buildings and interior spaces as well as outdoor facilities. Complete 2D images, such as floor plans, cross-sections and elevations, can be created from the three-dimensional scan data that is produced with the FARO Focus3D. These can then be imported, true to scale, into CAD programs. This makes it easy to compare the planning status with the existing building: possible planning errors are detected in good time and can be remedied before the construction phase. This avoids substantial liability risks and ensures that the major requirements with respect to accuracy and efficiency are calculable.
In the specific example of the aforementioned office building survey, significant differences are evident using the laser scanning method. In comparison with the existing CAD plan, clear discrepancies can be detected in the actual building in the region of the central supports and the right-hand exterior wall.
If such discrepancies are only noticed during future construction work, significant additional costs may be incurred and functional disadvantages in the design could arise. Instead the required planning certainty is achieved in good time using 3D measurements taken with the FARO laser scanner. The differences between existing and planned dimensions on all floors of this property amounted to approx. 30 square metres. A potential loss of rentable floor area was thus identified and communicated in good time. The accurate Focus3D measurement results were also to be used for the façade measurements. Following an analysis and direct comparison with individual manual measurements at sample points, it was found that the required accuracy of no more than 5 millimetres per window opening could not be reliably maintained with manual measurement. Discrepancies of between 0 millimetres and 15 millimetres were identified. However, the result could have been optimised still further by using tachometric calibration in parallel, but this would have involved a considerable amount of time.
The visual checking of axial grids, lintel heights and detail points was possible at an early stage of planning using overlaid scan data and the manually measured façade plans. This also represented a valuable aid in avoiding planning errors and ensuring a smooth construction process. The Focus3D measurements showed that the steel columns of the roof structure in this property (see image 2) are not centred over the masonry columns of the full floors. With this knowledge, the column cladding in the roof could now be positioned off-centre to achieve the desired uniform façade appearance.
The USP of 3D laser scanning with the Focus3D in comparison with other measurement methods lies in its ability to conduct integrated surveys of existing conditions and make multi-functional data analyses. Axonometric or perspective views from any standpoint can be generated from the scans. Video animations can be created with continually changeable camera tracks. The contents of the 3D scans also form a database for numerous innovative visualisation options.
As part of securing evidence, 3D scans with the FARO Focus3D serve to prove and portray the flatness of building components, for example. The areas shown in the picture in red are 2.5 centimetres in front of the reference plane. The areas coloured in blue are 2.5 centimetres behind it. This allows the state of the building to be accurately and incontestably documented, even after many years. 360° photographic-quality panoramas can be created with SCENE software, enabling visual and geometric analyses of the property. The quantity of data provided is so high that plans can also be prepared off-site. Visits to the building for follow-up measurements are rendered a thing of the past, saving time and money. As part of the bidding process, participating companies can view the high-resolution panoramas on the Internet, allowing them to submit accurately calculated bids. This also reduces construction costs. These panoramas can also be integrated into the architect's or client's home page.