# Innovative System for BIM/GIS Integration in the Context of Urban Sustainability
## 3 Materials and Methods
### 3D Model of the Building
#### 3.1.2 Interior  
For the modeling of the interior, conversely, we proceed to carry out the survey to produce a DWG file to be imported into the BIM modeling software. To create the 3D model of the building's interior, we started by importing the DWG file of the apartment plan, which had been previously created in AutoCAD. After positioning the building plan and selecting the appropriate level, we chose the walls from the \"Architecture\" section, ensuring they matched the specifications on site, including height and thickness. Indeed, Revit allows for aligning the walls with the contours of the DWG file, making the drawing process easier. In the same way as with the perimeter walls, we proceeded by inserting doors, windows, and floors, ensuring consistency with the conditions found on site.  
Once the survey has been planned and carried out, \"Faro Scene\" software is used, and the point cloud acquired by the laser scanner is processed according to a standard  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Feature** & **Specifications** \\ \hline Precision & \(\pm 3\) mm at 10 m and 25 m \\ Angular accuracy & 19 arcseconds (horizontal and vertical) \\ Scan speed & Up to 488,000 points per second \\ Maximum range & 70 m \\ Horizontal field of view & 360\({}^{\circ}\) \\ Vertical field of view & 300\({}^{\circ}\) \\ Laser class & Class 1 \\ Environmental protection & IP54 \\ Operating temperature & 5 \({}^{\circ}\)C to 40 \({}^{\circ}\)C \\ Storage temperature & \(-10\)\({}^{\circ}\)C to 60 \({}^{\circ}\)C \\ Weight & 4.2 kg \\ Dimensions & 230 \(\times\) 183 \(\times\) 103 mm \\ Internal storage & Supports SD cards \\ Battery life & Up to 4.5 h per battery \\ Automatic calibration & Included \\ Compensator & Integrated dual-axis compensator \\ Software compatibility & Works with FARO Scene and other point cloud \\  & processing software \\ \hline \hline \end{tabular}
\end{table}
Table 1: Technical specifications of the laser scanner used (FARO FOCUS).  
Figure 2: FARO FOCUS. Instrument used in the survey phase.  
methodology [38; 39; 40]. In relation to the building in question, Autodesk Recap software is used for converting the point cloud format (.E57) into a format compatible (.rcp) with the software program Autodesk Revit, used for 3D modeling of the building. Once the file is exported in.rcp, the 3D model is created using Autodesk Revit.  
The commercial software Infrawworks, which is used in the next phase, allows for users to import distinct types of digital records directly into the software if georeferencing information is available for those records. For this reason, a fundamental operation is the georeferencing of the model. Having opened the file containing the point cloud in Revit, the positioning is set to \"Automatic: with shared coordinates\" (Figure 3): in Revit, it is assumed that the point cloud file's coordinates are specified in the model's coordinate system, [41]. Thus, the point cloud origin aligns with the shared coordinates origin, accessible via the base survey point. The point cloud is oriented so that its north direction (0,1,0) matches true north in the Revit model. GIS coordinates are used to determine shared coordinates for different models such as the architectural, structural, and plant engineering models, ensuring the Revit model is correctly positioned relative to the site. These GIS coordinates define the model's real position in latitude and longitude (WGS84). Revit also uses GIS data for energy analysis and when exporting models to other formats. Once this is completed, we move on to the architectural modeling phase, which initially envisages the modeling of the terrain on which the building rests and the subsequent construction of the model by positioning the generic construction components and by gradually adding more detailed components.