Progression of Microclimate-Induced Degradation of Brick Façades Using Drone Imagery and Computer Vision

Paper in proceeding, 2026

Freeze-thaw degradation of brick masonry is a well-studied topic in laboratory settings but is more difficult to predict in real buildings. In practice, façades are exposed to various climate conditions, which differ even within a single façade. These variations are often caused by microclimate effects resulting from immediate surroundings and features such as roof overhangs. This variability makes it difficult to predict both the onset and the progression of damage using available numerical models and experimental procedures, highlighting the need for in-situ approaches. This paper presents a follow-up on previously detected damages using the PAIR framework, which assesses degradation risks across entire façades, in order to evaluate its capability for analyzing the progression of degradation over time and space. The methodology combines object detection and pixel-wise segmentation. Spatial matching of detected regions enables direct quantitative comparison between inspection periods. The methodology is demonstrated on a brick façade in Gothenburg, Sweden, inspected in 2024 and 2025 using drones. Results show an increase in the prevalence of spalling across 104 façade sections, providing insight into the rate of freeze-thaw degradation under real environmental conditions, and contributes to a broader understanding of masonry durability as well as method verification.