Real-time rendering is limited in the number of lights that can be used to shade a singular point, therefore it is crucial to select the most appropriate lights. To efficiently search through the large collection of lights a BVH tree is used, which contains positions and emissive characteristics of lights. Instead of rebuilding, an update process is used for animated objects. The update is faster, but it degrades the quality of the tree over time, resulting in increased rendering error. Therefore, the tree should be occasionally rebuilt. This paper presents four key attributes of the light tree, which can be quickly and easily calculated during the tree update process in every frame. They can be used to estimate the degree of the tree quality degradation. Two algorithms are proposed that can be used to decide on the necessity of tree rebuilding, based on the previously mentioned attributes. Applying those algorithms results in lower rendering error compared to a tree that has not been rebuilt, with a minimal number of rebuilds. At the same time, this solution is more versatile compared to rebuilding at fixed intervals.