The Working Area overhead is applied to Contractor employed people (as defined in People 1) who are working in the Working Areas. The percentage for Design overheads is applied to designers directly employed by the Contractor who aren't working in the WAs. Either way, on top of whichever percentage is applied, the direct fee percentage is applied
If the designers are not employed by the Contractor, then the Contractor is reimbursed in accordance with the subcontract. On top of this, you would apply the subcontracted fee percentage.
If the designers are not employed by the Contractor, then the Contractor is reimbursed in accordance with the subcontract. On top of this, you would apply the subcontracted fee percentage.