It’s simple psychology: a clean, well-maintained exterior signals that the entire property is cared for. Conversely, a dirty facade, stained driveway, or streaky roof can suggest neglect and potential underlying problems. Beyond just looking bad, mold and algae can actually be silently damaging your siding and other surfaces, leading to costly repairs down the line. Potential buyers (or even just neighbours!) notice these things, consciously or subconsciously.