“The average salary for a working man in the United Kingdom in 1971 was about £2,000 per annum. The average house cost about £5,500. By 1975, even in a relatively low-price housing area such as Leicester, a new three-bedroomed semi-detached house built by the Leicester-based Jelson Ltd was selling at over £7,5000.” – Stephen Butt, Leicester in the 1970s (2015), p.80.
In December 2015 the average house price was £188,270, while the average price of a house in Leicester was £172,000 (February 13, Leicester Mercury), which is of course substancially greater than the average salary which is not far off £20,000 a year.
For details of campaigns relating to housing justice, see http://www.housingworkers.org.uk/