Choosing roofing sheet for a soffit starts with establishing whether the eaves require an air inlet, as this determines the layout of panels and openings. Also check the geometry of the structure, the exposed face of the sheet and how it will be fixed to the supporting frame. The cost of the finish covers more than the sheet area: trims, flashings, fixings, ventilation components and work at corners all count. Drawing out the strip layout helps limit waste and shows whether offcuts can be reused. Remember that a soffit will not repair a leaking eaves – water ingress must be resolved before installation.