The potential social isolation of older people must be considered when encouraging them to downsize to free up housing for families.

The ESRI says there is limited scope for alleviating the housing crisis though such an incentive scheme.

It says many people over-50 live in what it's called relatively small houses so incentivising this group to downsize will have little impact.

Director of the ESRI Alan Barret says few older people are moving to smaller homes: