It doesn't help that there is no definition of what 'setting out' means in your contract, but I would suggest that it refers to providing a marked reference of the design on Site to facilitate the actual construction. For a reinforced concrete wall I wouldn't expect you to set out the positional locations of every item of steel rebar, for instance, but to provide reference points which enable the wall to be constructed in the correct place, as per the latest version of the design drawing.
The subcontractor's obligation under clause 20.1 does not change and I would suggest that the subcontractor is obliged to co-operate by agreeing the setting out points with you to ensure that they can fulfil this obligation.
The subcontractor's obligation under clause 20.1 does not change and I would suggest that the subcontractor is obliged to co-operate by agreeing the setting out points with you to ensure that they can fulfil this obligation.