A health expert says every branch of government needs to be involved in dealing with loneliness in New Zealand's ageing population.

Britain has appointed a minister for loneliness, to address the isolation felt by more than one in 10 Britons.

Otago University medical specialist Hamish Jamieson said our population is becoming older, more isolated and more fragmented.

He told Chris Lynch every government department and agency needs to be involved in addressing the issue.

"It's in lots of different camps. It's partly to do with housing, partly transport and urban planning, and also, to a growing extent, health and information technology."

He said New Zealand may need more housing where grandparents can live near parents and children.

"Make that sort of thing easier by having larger houses where multiple generations of the same family can live."

LISTEN TO HAMISH JAMIESON TALK WITH CHRIS LYNCH ABOVE