When choosing a site for a new tree, don't plant too close to buildings. Even smaller trees (up to 30 feet at mature height) should be planted at least 5 to 10 feet away from the side of a house or building. Larger trees should be even farther away — at least 15 feet. Otherwise, the trees don't have room to spread and develop their natural shape. In addition, aggressive roots can damage the foundation; falling limbs can damage the house; and rain gutters become clogged far more often.