# Using Dynamo for Automatic Reconstruction of BIM Elements from Point Clouds
## 4 Results
In a few cases, the beams were almost completely buried, or their profile significantly deteriorated by sea water and weather; in these cases, it was impossible to use the algorithm, and a manual modeling approach was chosen. Both beams and columns elements were modeled at the LOD 200 level of detail, which includes the correct type of structural concrete system and approximate geometry of structural elements (e.g., depth and width) [46], and does not include the sloping surfaces, connections, reinforcement, and other elements contained in higher LODs. When modeling the beams, the algorithm only reconstructs the section of points selected by the user, so at the end of the process, it is necessary to extend the start and end points of each beam to meet at the junction with the columns. This task is performed with Revit's \"extend\" command and takes little time and does not cause any model problems or inaccuracies. The building has masonry walls with a thickness variation from 110 mm to 140 mm for the interior walls and 225 mm to 250 mm for the exterior walls, and they do not show large deviations in their vertical axis. Internally, the walls divide the existing spaces that are currently empty and the existing bathrooms (Figure 20). The algorithm was able to digitally reconstruct almost all existing walls except for curved walls, as it was made only for recognizing straight-line walls, and a partition wall of the building's access gate with point cloud occlusions. The walls were created without the doors and windows, which were ignored by the algorithm and later manually inserted into the project. The code uses the wall family chosen by the operator and creates the specific family types with the appropriate thickness for each of the cases. If the chosen wall is a generic wall without layers, all the walls will follow this typology; if the choice is for a composite wall with the inner layers, the algorithm keeps the chosen wall layers and applies the thickness variation to the inner structure layer. The strategy developed for reconstructing the building's floors was slightly different from that used in the other elements. For this case, a combination of manual and algorithmic approaches was chosen according to pre-established criteria regarding the type of element, its function within the building, and the operating logic that the element performs within a BIM workflow. The algorithmic modeling developed aimed to reproduce all the deformities of the floors with great precision. Within the BIM methodology, this characteristic is not always expected or necessary because significant irregularities make it difficult to manipulate objects and compromise the proper functioning of subsequent operations. For this case, it was necessary to establish an acceptable level of model simplification, approximation, and tolerance according to the objectives for which the BIM model will be destined. The research identified which building floors needed to be represented without all the deformations, which would be modeled with the manual approach, and which floors would be modeled by the algorithm to represent all their deformities faithfully. The floors of the main floor and the access ramp were modeled manually and without the deformities on their surfaces, while the roof slab and a small access ramp at the front door were modeled by algorithm because we identified the representation of their deformities as necessary for this case. The BIM element created with the algorithmic approach is a floor family chosen by the operator and has all the physical and operating characteristics as the elements created manually. Besides outlining the components of the structure, we employed an algorithm to replicate the surrounding landscape of the building. By utilizing this algorithm we expedited the recreation process with accuracy, eliminating the need for manual adjustments to elevation points that would have otherwise been time consuming.