PurposeRegular inspection and maintenance is recommended to preserve and sustain built cultural heritage. Systematising inspection processes and knowledge on defects, and providing pictorial guides for evaluating defects is an approach that may facilitate their condition survey. Generating pictorial guides for preliminary visual inspection of Modern Heritage buildings with rendered-painted facade concerning two defects (i.e. crack and efflorescence) is aimed in this study. These guides are thought as aids in determining the defect levels and deciding the necessity of advanced examination and/or maintenance. Analysing briefly the evolution of crack over time in the inspected buildings under environmental conditions of Istanbul (Turkey) is also aimed.Design/methodology/approachPreliminary guide generation was based mainly on literature survey on defects, and visual data collection from eight Modern Movement examples in Istanbul. The guides were then refined through systematic visual inspection of three buildings among them. Evolution of crack over time was analysed through a second inspection performed after 2.5 years.FindingsVisual inspections showed that crack is the commonest defect occurring mostly on projecting structural members, while efflorescence is less in number. Comparison of cracks' visuals taken in the first and second inspections showed that deterioration process is slow.Originality/valueModern heritage buildings usually have some characteristic features, which may sometimes lead to accumulation of defects at certain locations or may lead to formation of certain defects. Generating visual guides as a start for an initiative for a comprehensive defects catalogue particular for Modern Movement buildings in line with associated cultural heritage standards may contribute to their preservation by easing the condition surveys.