(i) Increase in the growth of population and continuous migration of people from village to cities aggravated the problem of housing for the poor in big cities like London.
(ii) Factory or workshop owners did not provide housing for migrant workers. Though private landowners put up cheap and unsafe one room apartments or tenements on rent for homeless workers, these were unhealthy for the inmates. Gradually thoughtful people began to recognise the need for housing for the poor.
(iii) The report of the survey conducted in 1887 also concluded that London needed the rebuilding of at least 4,00,000 rooms to house the poorest citizens.
The main reasons of this concern was not wholly 'philanthropic'. The authorities realised that the vast mass of one room houses occupied by the poor were serious threat to public health, they were over-crowded, badly ventilated and lacked sanitation.
(iv) There was a widespread fear that poor housing may be a cause for fire hazards because of use of firewood or coal in every room.
(v) Some people even thought that with the spread of socialistic ideas (after Russian Revolution) workers unrest against poor housing might had to social tension.