Rendering below dpc

So I have a small extension to render. Still on a learning curve with it to be honest. They want it rendered below dpc, which I've said isn't the best idea but the builders are insisting on it. Normally when dashing I'd fit beads round dpc dash it then finish the base course with smooth cement keeping it back maybe 5 or 10mm so the water doesn't run down it. But with the render having to be 15mm it won't have an overhang above the dpc. What do you guys suggest?

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Rendering below dpc