Home ownership in the UK is overestimated by conventional data, with many more renters than the figures suggest, a think tank has suggested.

The official estimate of a 64% home ownership rate was too high, the Resolution Foundation said, as many people shared or owners had lodgers.

It said official figures concentrated on households, rather than people.

The think tank, which lobbies for low-income families, calculated that 51% of families or individuals own a home.

It is calling for more attention to be paid to the millions of others who rent.

"Our new analysis shows that we should perhaps obsess a little less about homeowners, and think more about how the other half live," it said.

It added that the number of family units owning their own home had peaked in 2002 and had been falling since.

It defines a family unit as an individual, a couple, or a parent or parents and their children. So one household with five single adults sharing is counted as five family units under the think tank's calculations.

The size of the private rental sector had been "massively underestimated" for this reason, the Resolution Foundation said. It estimated that 6.3 million family units rented privately.

The cost of renting a home from a private landlord in Britain rose by 2.3% in a year, according to the latest official figures. This was driven by a 2.4% increase in England, with the South East recording a 3.4% rise, the Office for National Statistics (ONS) said.

House prices rose by about 6% over the same period, surveys suggest.

The ONS says that in 2015, the latest year for which figures are available, there were 27 million households in the UK.

However, the Resolution Foundation said conventional housing data, as measured by the ONS, missed 5.8 million families or individuals who lived in somebody else's home. The vast majority of these (eight in 10) were adult children returning to live with their parents, it said.

The same think tank reported in August that major English cities - particularly Manchester - had seen the sharpest falls in home ownership since a peak in the early 2000s.

A spokesperson for the Department for Communities and Local Government said: "We've halted the decline in home ownership, with the number of first-time buyers up nearly 60%, and over 335,000 households helped into home ownership through government-backed schemes since 2010.

"We've also set out the most ambitious vision for housing of any government since the 1970s, investing £9.4bn over the course of this parliament. Our upcoming Housing White Paper will clearly set out how we plan to build the homes this country needs."

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