Padstone/Spreader Plate Design

[Egnorant]

I am reviewing a calculation for the design of mild steel spreader plate (or precast concrete padstone) for a steel beam to be supported on a masonry wall. Calculations are done as per BS5628. I believe, factored loads should be used to check the stresses under the padstone/spreader plate. However the designer has used unfactored loads and I am getting confused with this, especially because these calculations have been approved by local authority. Factored load will give a considerable large plate/padstone. Note that the wall in question is a party wall and only a limited width is available to site the steel beam. I have done my calculation, which are attached. I'll appreciate if somebody could take his red pen out and comment on it.Thanks