repace fascia board on a rendered wall

[windyboarder]

Hi all, advise please.. have a (rotting) wooden fascia board, on a rear sloping extension roof, nailed to joists (no soffit) and the wall has been rendered up to the bottom of the board (which juts out over the render along its length). So when replacing the fascia board is it best to use a wider board such that it overlaps down over the render a bit, or a similar width board but just ensure it juts out as before (this will require some sort of padding as the pvc replacement is not so thick). Have had conflicting advice, any ideas please? thanks wb