2 X SDP for married couple

We have a married couple both getting AA. They live with their daughter and son in law.
If they lived in their own household they would qualify for a double SDP on any PC.
Does the double SDP apply when they live in their daughters home?
Its probably staring me in the face but its been a difficult Monday…

Unless daughter & son in law are in receipt of a qualifying benefit then the answer would be no.
Check out CPAG pg. 228 or DRH pg. 142 onwards for the possible SDP permutations.

maybe if they are joint tenants they could get the premium