It will primarily depend on the roof.
Roof overhang without soffit.
Roof overhangs are the amount that the roof hangs over the top of the siding in residential home construction.
On buildings where the top of windows are close to the top of the building wall there may be insufficient space to construct an overhanging roof eave without blocking the windows.
The venting drip edge seems to be the easiest and most common way to go.
Tips for roof eave venting on roofs with no overhang or soffit dci products.
Venting a roof without eaves.
Proper locations for another sketch of soffit construction and soffit ventilation details.
This is usually a 3 8 inch piece of plywood that is underneath the overhanging portion of the roof that extends beyond the outside wall.
The siding underneath the overhang is known as the soffit.
Overhangs are common in most house designs providing protection against both wind and rain.
Un vented roof solutions to buildings with no roof overhang and which are a more distant second best approach are discussed at roof venting.
Some home designs do not have a soffit.
Un vented hot roof solutions.
Smart vent 6 step installation guide by dci fine homebuilding.
With a soffit venting is not much of a challenge.