A vented soffit is important since it provides ventilation and adequate ventilation is needed in attics; the rule of thumb is one square foot of ventilation area for each 150 square feet of attic floor area. Attic ventilation is needed to prevent condensation problems in the cold winter months. Also, there must be an equal amount of area that lets air in as the area that lets the heated air out. Soffit vents allow cool air to be drawn in, heated by convection and escape through roof vents, such as ridge vents and/or gable vents. Rectangular vented soffit panels do the job, but they are old-fashioned looking.
One alternative is to use continuous soffit strips. They are available in aluminum or plastic and come in 96-inch lengths by either 2 inches or 4 inches in width. Different colors are available. They are simple to install with a circular saw. The saw blade should be set slightly deeper than the thickness of the wood. Snap a chalk line and cut and screw the soffit strips to the eave. Another option, which some people might prefer, is to use round soffit vents. They are quite easy to install by using a hole saw and they come in different diameters in both PVC and aluminum.