They are thick and dense and serve as a barrier wall that can't easily be passed through. Evergreens, when used for hedges are excellent for wind breaks in open spaces where damaging winds threatens storage buildings, lawn and patio furniture and other garden or year fixtures. They make great noise reducers. If you live by a busy street or near very loud neighbors, evergreen hedges are wonderful for blocking out noise.
Evergreen trees, if planted 4-6 feet apart will enclose your pool area where no one can see. What an enjoyment it would be to be secluded from the public eye while swimming & sun bathing. They also provide beauty all year long. When all other trees and plants have lost their leaves in fall and winter and your landscaping looks bare, evergreen trees stay beautiful year round.