Nearly a fifth (19%) of people are spending more than half of their monthly net household income on housing costs such as mortgage or rent payments, utility bills and council tax, Engen Group has found.
Some 4% of over 75s spend more than half of their monthly net household income on these costs.
In terms of gender, the figure is 26% for women compared to 13% of men.
Graeme Boiardini, chief executive of Engen Group, said: “Our findings are very alarming but given the housing shortage in the UK not entirely surprising.
“Thankfully building more affordable housing is at the top of the political agenda, so hopefully over the next few years we will see significant inroads being made into tackling this problem.”