This review systematically examines how lean management is applied in construction worldwide, distinguishing explicit (conscious) lean methods from implicit (subconscious) practices. Peer-reviewed studies and white papers were surveyed on lean construction, focusing on tools like Last Planner System (LPS), Value Stream Mapping (VSM), Sort, Set, Shine, Standardize, Sustain (5S), Kanban, and pull planning, as well as on everyday waste-reduction habits (e.g. material reuse, concurrent tasks) that align with lean principles. Results show that explicit lean methods (LPS, 5S, VSM, Just in Time JIT delivery) are well documented to improve predictability, productivity, quality, and sustainability. Subconscious practices (e.g. salvaging steel cut-offs, scheduling trades in parallel) similarly reduce waste, reflecting lean thinking even when not labeled as such. Key findings indicate that large firms and countries with mature construction markets (US, UK, Scandinavia) adopt lean more consciously, whereas in many regions lean gains occur informally or through analog methods. Common barriers to conscious lean adoption include lack of top-management commitment, low awareness/training, and insufficient systems support. We propose that targeted leadership engagement, education, and integration of lean tools into standard practice can bridge gaps between implicit lean behaviors and formal lean implementation. This review highlights both the extent of lean thinking embedded in construction practices and the challenges still limiting its systematic adoption.