How often should your office windows be cleaned? Well, it depends which areas your office is based. All parts of the UK see a significant amount of rainfall in a year, but some areas see more rain than others. In areas of higher rainfall, office windows may need to be cleaned more regularly due to the mineral deposits in rainwater, which can leave smudge and stain marks on windows. If your office sits near a busy road where traffic volumes are high, over time, a build-up of traffic film will make the windows look dirty. Alternatively, if you are based in a village or a quieter location in a town, then your windows shouldn’t need to be cleaned as often.