Analysis by warranty provider LABC Warranty has found that the average living room is now 17.09sq m, which represents a drop of 1.64sq m in the past decade and a huge decrease on the peak average size of 24.89sq m in the 1970s.
New living rooms have not been so small since the 1930s, when they were 16.01sq m, and bedrooms and kitchens have also shrunk.
The average master bedroom is now 13.37sq m, which are the smallest on record in the last 80 years, and there are fewer bedooms overall, too.
Homes built in the last seven years have had less than three bedrooms each on average, with new properties in all other decades since the 1930s having had at least that many.
Kitchens have also got smaller, at an average size of 12.61sq m, which is way down on the 15.37sq m enjoyed homeowners in the 1960s.
It all means that at 46.01sq m, today’s houses are smaller than in any other decade, adding further fuel to a previous assessment by the Royal Institute of British Architects that too many homes in Britain are being built like rabbit hutches.
The figures analysed by LABC Warranty are based on data from property sites Rightmove and Zoopla, with the study having begun with homes built in the 1930s due to insufficient records from prior decades.
UK houses prior to the Second World War were relatively small, with the 1950s marking the start of a “housing revolution” due to increased demand for property.
The rate of growth continued into the 1960s, with complaints of shoddily designed tower blocks pushing developers towards the more straightforward, “box-like” homes that have maintained their popularity ever since.
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But house sizes have steadily declined since the 1970s, when living rooms were at their biggest and the average UK home boasted a greater overall number of bedrooms than ever.
“Today, Britain’s houses have never been smaller,” the firm’s analysis concluded.
“Compared to the previous decade, homes built from 2010 onward are over 4sq m smaller. Our analysis of the first seven years of the decade is continued regression.”