Similarly, offsets can also be applied to the bottom. This is common in methods where the siding is applied a few inches above grade. Note that the offset also applies to the sheathing material used. (e.g. OSB)
Offsets have the effect of reducing the overall area reported and reflected in the purchase orders. Panel lengths in panelizsed siding types (e.g. steel) may be reduced as the desired result. Re sheathing, this is always calculated in terms of square footage, so offsets tend to reduce the square footage needed if they are applied (clicking the YES checkboxes.)
