By contrast, four in ten UK adults have no property wealth at all, the Resolution Foundation says.Read more
Personal Finance reporter
BBC Radio Cornwall
A proposal to charge second home and holiday let owners in Cornwall up to double the standard Council Tax could raise up to £25m to build affordable homes in the county.
Labour Party campaigners have started a petition arguing that second homes are pushing up the prices of all housing in Cornwall, not just in resorts such as St Ives (pictured) and St Mawes.
Labour Councillor Cornelius Olivier said it was a fair proposal if the money raised was spent properly.
He said: "I think it's fair if the money is used to provide housing because, whatever economic benefits we get from holiday lets, the impact they have on the housing market down here - and the availability of housing for local families - is enormous."
A petition's been started calling for second home and holiday let owners in Cornwall to pay up to double council tax.
In parts of the county, about 50% of the housing isn't permanently lived in, and some argue it's destroying communities.
Labour Party campaigners want local authorities to have the power to charge extra council tax and use the money to build social housing.
They said they wanted the county's six Conservative MPs to put pressure on the government.