Homes in England cost nearly eight times the average wage typically, while those in Wales equate to nearly six times average earnings.
In 2020, full-time employees in England could expect to spend about 7.8 times their workplace annual earnings on buying a home, according to calculations from the Office for National Statistics (ONS).
In Wales, a full-time worker could typically expect to spend about 5.9 times their workplace-based annual earnings on purchasing a home.
The ONS said the figures were not significantly changed compared with 2019.
Since 1997, housing affordability has worsened overall, it added.
New builds tend to cost a higher multiple of average earnings than existing properties.
In 2020, full-time employees in England could expect to spend 9.6 times their gross annual earnings on purchasing a newly built property and 7.6 times their annual earnings on an existing property typically.
In Wales, full-time employees on average spent 8.2 times their gross annual earnings on a newly built property, and 5.7 times their earnings for an existing property.
Looking at properties generally, Copeland, in the North West of England, remained the most affordable local authority in England and Wales in 2020.
In Copeland, the average price paid for properties was estimated to be 2.6 times average annual earnings. This was a slight decrease from 2019 but not statistically significant, the ONS said.
Kensington and Chelsea, in London, remained the least affordable local authority in England and Wales, with average house prices estimated at 36.4 times average annual earnings. This was a decrease from 2019 when house prices were 39.3 times annual earnings.
Nottingham was the only local authority in England and Wales that had a statistically significant change in the ratio of average house prices to average workplace-based annual earnings over the five years between 2015 and 2020, the ONS said.
In Nottingham, affordability significantly worsened, going from 4.33 in 2015 to 5.16 in 2020.
Sarah Coles, personal finance analyst for Hargreaves Lansdown, said the average house price varies enormously – not only in terms of where people buy but also regarding the type of property they want.
She said: “The most recent ONS figures show the prices of detached houses have boomed 8.6% in a year, while the price of flats is up just 2.6% over that time. It means those trying to sell a flat and buy a house have an even bigger mountain to climb.
“When it comes to wage rises, averages can be misleading here too. While the average wage increased significantly in 2020, this was partly because so many of the jobs that have been lost to the crisis are low-wage roles. This automatically pushes up the average without people actually getting a pay rise. It means in reality, affordability may be even lower.
“And all this has come at a time when mortgages for those with smaller deposits have been even thinner on the ground.
“Fortunately, things have picked up from the start of 2021, with more lenders returning to the market over the past few weeks. The Government’s offer to guarantee 95% mortgages will help support this end of the market still further.
“However, there are still restrictions on many of these mortgages. Some 95% mortgage lenders, for example, won’t lend on flats or new builds.”