The need for observation and ventilation meant opening up the city, improving the process of circulation much as an individual's health depended on the circulation of blood and oxygen. One answer was to demolish slums, by driving railways to the new stations or building new roads to allow the passage of traffic. Hence the decision to build Shaftesbury Avenue in London's West End, cutting through some of the worse slums of Soho.

　　Little was done for the wretchedly poor people who lost their housing during the process, and they were obliged to huddle ever closer in the next block of housing. Some charities - most famously the Peabody Trust in London - built new model housing on the cleared land, but to little avail. The new housing often consisted of grim, forbidding, barrack blocks, and rents were high, so the poor could not afford to live in them. At the end of the 19th century, however, some local authorities did start to build council housing, which offered a new solution to the problem of housing the poor.

　　'Punch' cartoon, 1854: King Smoke Despite the continuing problems of poor housing, conditions did improve from the 1870s, with the construction of new, healthier housing.

　　The Public Health Act of 1875 required local authorities to implement building regulations, or bye-laws, which insisted that each house should be self-contained, with its own sanitation and water. This change in the design of housing complemented the public investment in sewers and water supply.