Contemporary building documentation increasingly relies on laser scanning technologies that provide rapid and precise spatial data acquisition. Portable LiDAR systems such as the Leica BLK360, as well as mobile devices like the iPad, offer modern tools for efficient documentation of interior spaces, including office rooms. With dedicated applications (e.g., Leica Cyclone Field 360, Leica Cyclone 3DR, MagicPlan, BIMx, AutoCAD Mobile), users can record measurements, create sketches, and generate 3D models and photographic documentation within a single digital environment. The purpose of this study is to assess the dimensional accuracy in the documentation of an office space using portable LiDAR systems. The experiments showed that, for most analysed dimensions, the results agreed within several centimetres, which is sufficient for architectural inventory work. However, the issue of rounded corners was identified, which may significantly influence measurement results depending on the distance-measurement method applied. Reliable accuracy analysis required proper mutual alignment (common georeferencing) of the scans acquired with the selected instruments. To achieve this, point cloud classification was performed to identify surfaces suitable for cloud-to-cloud alignment. A predefined AI-based classification model dedicated to indoor environments was used. The findings confirm that portable LiDAR systems significantly reduce the time required to complete inventory tasks and enable more comprehensive visualisation of interior spaces. This technology serves as an effective tool supporting the design, modernisation, and management of office environments in a digital workflow, although its accuracy-related limitations must be considered.