The eave is the part of the roof that meets or overhangs the walls of a structure. It is also considered the bottom edge of a roof. The eave projects beyond the side of the building and throws water clear of the wall. This eave may be decorated as part of an architectural style to match the look of the home.
The primary function of an eave is to keep rainwater off the walls of the structure and to prevent any ingress of water where the roof meets this wall. They also protect pathways around a building from rain. Eaves can also help to prevent erosion of footings and reduce the amount of splatter on the wall from rain when it hits the ground. A secondary function of eaves is to control solar penetration and they can be designed so they can adjust to the solar heat of the building and the particular climate of the structure.
In terms of design, traditional and decorative considerations oftentimes are more important than the function. An eave may terminate into a fascia, a board that runs along the length of the eaves underneath the tiles or roof sheets to protect any exposed rafter ends and also to provide stability where gutters may be fixed. The eave should be evaluated regularly to guarantee its function.