Surveying techniques for large-area mapping such as airborne laser scanner have been used to measure changes via 3D point cloud comparison. We implemented into Terrasolid software module TerraScan an approach for the detection and visualization of 3D topographic change using openly available airborne laser scanning (ALS) data from Finland. This approach is applied to two point cloud epochs (from 2017 and 2021) to identify and analyse changes related to city area — revealing disappearing trees, new buildings, and even small extensions to existing structures. In TerraScan, this process is driven by a special distance-based attribute called "Change", which quantifies differences between new and reference point clouds.This change attribute is computed automatically, stored in the project definition, and visualized using intuitive color schemes—making it easy to spot changes at a glance.TerraScan also offers advanced color mapping to highlight subtle structural differences.For large-area monitoring, multiple TerraBatch instances can run in parallel, dramatically accelerating the change detection process at the project scale at the top speed.