The Influence of the Surveying and Documentation of Buildings Geometry to Different Investigation Purposes 
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Hand-based measurement 
Architectural drawing 
Figure 1: Traditional architectural surveying for historic building research 
Photogrammetry 
Tacheometry 
Figure 2: Modem surveying and documentation methods 
Laser-scanning 
Since Meydenbauer photogrammetry is an often used method to survey historic objects. Photogrammetry is characterised by a short 
surveying time at the object and a large one in the office during the photogrammetric evaluation. The surveying job is normally done 
without any contact to the object so that an intensive investigation of all parts of the object which cannot be seen doubtless in the 
photos is impossible. 
The second modem surveying method is the electronic tacheometry which can be carried out with or without reflector. The 
reflectorless tacheometry seems to be a very good method for surveying historic monuments because nearly all object-points can be 
measured standing in front of the object but without direct contact. Additional evaluation in the office is normally not necessary, but 
there are some difficulties during the measurements caused by the signal reflection and point selection. The advantage of the 
reflector-based tacheometry is the possibility to select the measured points very close to the object. Therefor the point selection can 
be done considering additional, not obviously visible object characteristics. 
The more and more used laser scanning methods allow an automatically surveying of the object in a very short time with the result of 
an unstructured and non-interpreted data set. 
With these mentioned above and all other modem surveying methods the geometry of the object can be measured. The buildings 
geometry is the most obvious building characteristic and because of its visible dominance it seems to be easy to survey it. For the 
conventional part of geodesy and photogrammetry - which is not very specialised in recording historic objects - the characteristic 
points of a building, the lines and edges seem to be the most important geometric parameters that describe the buildings geometry 
and therefore the building itself. But are photogrammetrists and geodesists really able to survey historic objects with their knowledge 
of architectural shape, architectural style and the specific building construction? 
3. SURVEYING AND DOCUMENTATION AS A MODELLING-PROCESS 
To answer this question it seems to be useful to analyse the processes, which are relevant during a surveying or documentation 
process. 
The recording of historic buildings can be compared with a general modelling process, that should be provide an useful model from a 
complex original object. Common modelling processes that take part in many scientific areas are investigated very well in the so 
called 'modelling-theory'. In the modelling theory the original object is characterised by many different attributes. During the 
modelling process it is impossible to transfer the original with all its attributes into the model. It is shown in the left part of the figure 
3 that only a few elements of the object characterising parameters can transfer to the model. Some attributes of the original are not