When starting new construction projects around your house, don't forget to think about the impact on the surrounding plantings. Running equipment back and forth over root zones will result in compacting the soil. Storing material or piling construction spoils around the base of the tree will further this compaction which can limit the oxygen getting to the root zone and hurt your trees. A good rule of thumb is to stay as far away from the trees as possible. Often times this just isn't possible with limited work areas, but putting some protection like fencing around the trees will help insure at least a minimum distance is kept. This will also help minimize any mechanical damage to the tree itself.