I would love to hear an expert response to my off-the-cuff idea this morning in response to the above. Namely, a national programme to improve properties belonging to poorer owner-occupiers with something like the equivalent value from any future sale going back into the scheme. If equal to or exceeding the value of the property, maybe it could become council housing at the point the owner-occupier vacates (e.g. care home or death).
Some prospective inheritors might balk!