Kate Godfrey, a widow from Cheshire, dreams of swapping her busy family home for a little cottage in the country, surrounded by a menagerie of rescued animals. At 56, with her four children now aged between 21 and 31, the copywriter might reasonably have expected to be contemplating a smaller home and the next stage of her life.

Instead, three of her four adult children are still living under her roof, with only her youngest, Eliza, having fledged the family nest. Kate is one of a growing number of parents whose plans to downsize are being complicated by adult children who either cannot afford – or simply aren’t ready – to move out. Nearly one in five UK homeowners aged 50 and over have downsized, close to four million people; but an estimated three million people aged 65 and over would like to move to a smaller property but haven’t, with everything from a shortage of suitable homes to moving costs and emotional attachment stopping them.

There can be a lot of zeros at stake when it comes to making the move. Research by estate agent Jackson-Stops found that moving from a detached house to a semi-detached property could unlock an average £209,215 in equity – rising to almost £790,000 in expensive areas such as Elmbridge in Surrey.