In R(Carmichael and others) v SSWP the Supreme Court found (finally) that the housing benefit size criteria/bedroom tax were discriminatory insofar as they failed to make allowance for couples who are unable to share a bedroom because of disability.    The SofS has recently legislated to amend the relevant regulations with effect from 1 April 2017 (by making the Housing Benefit and Universal Credit (Size Criteria) (Miscellaneous Amendments) Regulations 2017).  But here's the catch; the DWP are maintaining that the changes cannot be backdated to before 1 April 2017 - see  HB Circular A3/2017, revised 27 March 2017.  Presumably they take the view that the pre-amendment regulations cannot be read down so as to cure the discrimination under section 3 Human Rights Act 1998.  My own view is that that is wrong.  In the case of private or housing association tenants the key provision is Regulation 13D(3) of the HB Regulations 2006.  Subparagraph (ba) makes provision for the additional needs of certain disabled children.  It is difficult to see how that could be read down so as to apply to couples.  But that is not necessary.  In fact the discrimination arises from Reg. 13D(3)(a), which requires each couple to share a room.  I see no reason why that paragraph cannot be read down, or disapplied entirely, in respect of disabled couples who cannot share because of disability.  It would then follow that each member of the couple qualified for their own bedroom as an adult (13D(3)(b)).

No doubt the Upper Tribunal will take a view on this in due course.  I gather a number of appeals are pending.