An estimated 4.8 million households across England have housing affordability problems, a report has found.
This equates to more than one in five (21%) households across the country, according to the findings from the Affordable Housing Commission.
Households with dependent children make up more than half (57%) of households facing housing affordability problems.
The Commission said that when rents or purchase costs exceed a third (33%) of household income for those in work, it can lead to financial difficulties, arrears, debts and other personal problems.
It said the problems become critical in cases where housing costs eat up 40% or more of household income.
In the private rented sector, four out of 10 of all those in the bottom half of incomes are paying more than 40% of their household income in rent, the report said.
It estimated the number of households with affordability problems has increased by more than half a million since 2010, with the largest upswing coming from the private rented sector.
The Affordable Housing Commission was set up by think-tank the Smith Institute with the support of the Nationwide Foundation, to examine the causes and effects of the housing affordability crisis.
The report also estimates that there are 1.6 million renters, mostly in the private rented sector, who could afford to buy a home but are unable to, mainly because of the need for large deposits.
Lord Richard Best, chairman of the Affordable Housing Commission, said: “The term ‘affordable’ has become a much-abused word in housing circles. Successive governments have taken it to mean ‘rents or purchase costs which are lower than in the open market’.
“But paying rents of, say, 80% of the market level is still far beyond the means of many who need a home.
“At a time of national concern about levels of poverty and inequality, our Commission wanted to find out how people’s housing costs are fuelling the situation.
“We have looked at the scale of the problem and redefined measures of ‘affordability’, to take into account the impact it has on people’s lives, looking at what people can pay for housing without risking financial and personal issues.”
Greg Beales, director of campaigns at Shelter, said: ”Few people are immune to our housing emergency, which has seen the cost of keeping a roof over your head sky-rocket over the years – especially for those in lower paid jobs.
“A dwindling supply of social homes has produced a surge in people forced to pay expensive private rents…
“It’s painfully clear we need an alternative to private renting, and that alternative should be a new generation of social homes.
It’s high-time we saw social housing for what it could be – a step up for families desperate to get on in life.
“That’s why Shelter is calling on the Government to deliver 3.1 million social homes over the next 20 years.”
Local Government Association housing spokesman Cllr Martin Tett said: “Housing security is critical for the health and wellbeing of families and everyone deserves a safe, secure and affordable place to call home…
“At the most acute end, councils are currently housing over 200,000 homeless people in temporary accommodation, including over 120,000 homeless children.”
A Government spokeswoman said: “We are committed to making sure the housing market works for everyone.
“Since 2010 there have been more than 400,000 affordable homes provided in England, but we’re aware that more needs to be done, which is why we’re investing over £9 billion in affordable housing and an additional £2 billion after 2022.”