A clean building is better looking than a dirty one, because it presents a more hospitable front and a more attractive real estate prospect to the public. A building will always look best when it´s free of the pollutants, stains and grime.
Depending on its commercial activity (business, theatres, shopping malls, etc), they will often need a higher degree of cleanliness compared to buildings that house less public activities.
Depending on its geographic location, function, and atmospheric conditions, the level of cleaning effort varies to keep the building clean, but not all building facades have the same amount of care and attention, so it´s important to consider all the conditions to keep the desired appearance of the building.
While aesthetics is the primary reason for cleaning a building facade, the effort to expose the substrate for evaluation and repair runs a close second. In order to determine those areas that need maintenance, the facade should be cleaned of all elements that preclude its proper evaluation. Also cleaning the facade slows down the deterioration caused by damagin pollutants sucha as sulfur and nitrogen oxides.
Facade cleaning opens a building´s pores and allows the normal transpiration of moisture, so comprehensive facade cleaning must include removal of the waterproofing coating as a key component in a professional effort to restore the building.