According to the National Office for Statistics, in 2013 19% of all owner occupied properties in the UK were 4 bedroom properties. However only 14% of owner occupied property was found to have a household of four people. These statistics have played themselves out in the following years as a shortage of affordable and available 4 bedroom houses for young families with a great deal of older owners whose children who have since moved out still occupying larger houses with empty bedrooms.
The lack of four bedroom houses on the market has been put down to many factors such as a lack of incentive and appropriate downsizer houses for the older generation currently occupying the 4 bedroom housing stock as well as house price inflation rendering the typical 4 bedroom detached house too expensive for young families. According to a House of Lords report from 2015 another factor in the scarcity of 4 bedroom houses are the government's low new build targets and lack of availability of capital to local authorities to build new homes.