The number of flats being built in the UK is increasing rapidly, and single story living now makes up 23 per cent of all housing.

According to a new report by Royal Mail, the total number of flats rose by 4.2 per cent during the last four years, while the number of houses in he UK only increased by 2.5 per cent.

Royal Mail reports that 33,220 new ‘multiple residencies’ were added its Postcode Address File (PAF) between April and December last year – an 18 per cent increase on the same period in 2015.

Flats make up more than half of all housing in London (54 per cent) – the highest share of anywhere in the country. The capital also has the most flats (1.89 million) and the greatest increase in the total amount of them, up 5.8 per cent in the last four years.

The East of England – which includes Hertfordshire – came second, behind London (57 per cent) in the list of UK areas with the biggest average flat price increase, up 43 per cent to £188,380 in the four years to August 2016.

Steve Rooney, head of Royal Mail’s Address Management Unit, said: “While the distribution of property types has been relatively stable for the last four years, the number of flats has grown more than any other property type.

“This rise is most likely due to high land prices limiting the possibility of building semi-detached and detached houses.

“The number of multiple residency additions has increased steadily over the last nine-months and we fully expect this trend to continue for the near future.”