For most clients we clean the windows every four weeks as we have found this to be the best frequency to maintain the cleanliness - this also costs the least. A few clients have an eight- weekly clean and even fewer have us clean every twelve weeks; however, we charge more for these intervals as there is more dirt to clean off and the time increases. We also cater for one-off cleans. We will explain the best frequency when we give you our quote - we can discuss your requirements at that stage.