CIPA 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
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Tacheometry necessitates special skills and therefore 
specialist building surveyors. 
The building survey therefore has to be delegated to 
experts. These experts know their craft but may not have 
sufficient knowledge concerning planning requirements or 
be able to identify specific problem areas. 
The survey is seldom extended with specific more detailed 
information during the planning and renovation process. 
Once the specialist surveyors are finished the survey is seen 
as completed. In addition, planners and researchers do not 
have the necessary skills to extend the existing survey in the 
same way. 
2.3 Laser-Scanning 
Laser-scanning is a special technique associated with reflector 
less tacheometry in which an object or part of a building is 
scanned resulting in a high-resolution ‘cloud’ of points. The 
disadvantages of the system are similar to those of reflector-less 
tacheometry with some notable additions: Laser-scanning 
results in a high-resolution description of a surface geometry 
from which building-relevant parameters have to be deciphered 
in a second-step. This post-modelling is still in the 
developmental stage so that laser-scanning is not practical for 
building surveying at present. In a later section we will come 
back to a special application for laser-scanning in the surveying 
of building detail. 
2.4 Photogrammetry 
Photogrammetry using stereo-image or multi-image 
photogrammetry is rarely used for most building surveying 
projects, primarily due to its high cost, the need for specialists 
and the post-processing requirements for its assessment. In 
principle stereo-image photogrammetry is suited for measuring 
the geometry of irregularly structured building details. 
The rectification of single-image photogrammetric results is 
suited for surveying building surfaces. It is a quick means of 
measuring a large amount of geometric correct information at 
high-resolution. Rectification does, however, have limitations 
when measuring irregularly structured surfaces. Developments 
in conjunction with laser-scanning approaches are still in the 
early prototypical stage. 
All photogrammetric approaches require a direct visual contact 
between the camera and the area to be measured. Areas which 
are covered up or surfaces which fold back on themselves 
cannot be measured. 
As with tacheometry, the direct tactile contact to the building is 
lost. Where cameras with insufficient resolution are used, object 
information within the image may not be recognisable. 
We can conclude that geodesic or photogrammetric approaches 
are well-suited for establishing an initial survey. These can be 
used to develop an overall geometric model and to provide an 
geometrically-corrected basis for basic charting requirements. 
Its most important contribution to the building survey is the 
provision of a high-level geometric reference system to which 
all further geometric measurements can be related. 
3. DEFICITS 
The examination of the characteristics of traditional and 
conventional measuring approaches show that they have no or 
only limited suitability for the supplementary measurement of 
small-scale details. A whole area of surveying remains 
unaddressed, which at present is covered by supplementary 
sketches, direct modelling (profile measure, plasticine etc.) or 
more complex measurement using string, plumb-line and 
measuring stick. These traditional manual techniques also have 
particular disadvantages: 
Sketches only provide geometric information where the 
drawing has been annotated with geometric measurements. 
Supplementary sketches cannot be integrated as geometric 
data in the digital building model. They can be used as a 
descriptive attribute attached to a particular building 
element. 
The exact spatial location of the measured information 
cannot be determined. 
These disadvantages are most noticeable in the surveying of 
details such as profiles, capitals and other complex and non 
standard building elements (windows, doors etc.). A reliable on 
site survey of each individual situation is fundamentally 
important for the assessment of building renovation works, for 
instance for the repair, extension or reproduction of building 
elements and details. Ornate building elements, often made of 
multiple elements are particularly common in the renovation 
and conservation of historic buildings and are difficult to survey 
using traditional approaches. 
4. NEW TECHNIQUES FOR BUILDING SURVEYING 
This gap in the coverage of geometric building surveying can 
be addressed by tactile surveying methods adapted to the 
requirements of existing buildings (Fig. 1). 
Figure 1: Tactile building surveying 
Manual building surveying methods can play a significant role 
in conjunction with modern tactile surveying tools. 
4.1 The integration of tactile approaches in a system for 
building surveying 
Before individual approaches can be examined in detail, tactile 
surveying methods need to be integrated into the overall 
surveying approach. The integration of tactile approaches into