This is useful when a customer wants to keep the tree long term but it has become too big for its environment. The canopy of the tree may be overgrowing onto a building, neighbours property or public highway. We would usually recommend a reduction of the whole canopy by no more than a third but sometimes more, depending on the degree of the problem.
Sometimes it is not necessary to reduce the height of a tree and Crown Thinning maybe a better solution. Some people decide to reduce the crown (height) of a tree but often thinning makes for a suitable alternative.