Set the wall location line to match the dimension type
Match the wall location line to the dimension you need so outer-to-outer, inner-to-inner and centre-to-centre values measure from the intended face.
For outer-to-outer dimensions, the wall location line should be set to the outer face, just as inner-to-inner dimensions use the inner face and centre-to-centre dimensions use the wall centre.
Set the location line before typing the dimension so the entered value is measured from the intended face.