The 20th century in Britain involved a move from the Victorian laissez-faire attitude to the belief that the government plays a role in ensuring people lead healthy lives.

The problem identified:

When the Boer War (1899) broke out, many army volunteers were unfit to serve
The state of these volunteers led to the investigation of living conditions and the health of ordinary people living in industrial cities
Various social surveys were carried out which highlighted the extent of the problem
Booth's Life and Labour of the People (1889) found 35% of London's population were living in abject poverty
Rowntree carried out work in York; 1897 and 1898 his researchers interviewed 46,000 citizens of York
Rowntree's results were published in Poverty. A Study in Town Life (1901) - nearly one-half of working citizens in York lived in poverty
Another book which changed the opinions of many at this time was Round About a Pound A Week (1913) published by Reeves

Progress after World War One:

Housing Act 1919 proposed the building of 500,000 homes 'Fit for Heroes'; these homes were only half built
In the 1920s and 30s, there were subsidies for building council houses
While acts of parliament encouraged the demolition of slum properties, the inter-war year economic difficulties halted this process
1939 - 1 million houses had been built by workers to live in
Damage and destruction from the Second World War made the demand for 'affordable' housing even greater