City planners cannot be expected to concern themselves with such matters as are summarized under 3 and 4. It is for health and housing authorities to enforce repairs and cleanliness and to prevent overcrowding. Visiting housekeepers, the schools and the public press must be relied on to build up gradually a better standard of hygiene within the home.
With the residuum, however (slum conditions produced by faulty layout or by faulty structural plans in respect to light and air), the city planner ought to concern himself very deeply, for he alone holds the key to the solution. It is strange that his imagination has been so little stirred by the opportunities offered. A slum section is a liability to a community from every point of view - physical, mental, moral, industrial, economic. It does not tend to rehabilitate itself through the ordinary workings of supply and demand. The people who live in slum sections cannot afford to pay a profitable rent on new houses. Therefore none are built for them. Nor will better-to-do people move into such neighborhoods. The New York Commission of Housing and Regional Planning calculated that, on the basis of the 1909-1925 rate of demolition, it would take the "old law" (pre-1901) tenements of New York 138 years to disappear. When we are told that the average life of a building in the United States is something like 25 years, such reference is not to slum sections, where stagnation is the rule, but to the regions of most rapid development, such as those occupied by costly skyscrapers.
1 Structural inadequacies consisting of lack of proper toilet or bathing facilities may ordinarily be remedied without demolition where water mains and sewers exist.
The writer's thesis is that the only cure for slums of classes 1 and 2 lies in muncipal clearance schemes, and that these should form, not isolated activities of the health and housing departments, as is necessarily the case in Great Britain under existing town-planning limitations, but an integral part of every city plan which deals with an already existing community.
It will be useful at this time to consider: What is slum clearance? Where is it? Does it pay?
Slum clearance is the acquisition by city or other authorities of slum areas declared injurious to public health or morals, followed by demolition and a new layout of streets and open spaces. Usually, the same authority builds new accommodations, on the site or elsewhere, for as many persons as have been displaced by the clearance. This is mandatory in Great Britain.
Slum clearance, undertaken as a health measure, is found in many European countries, but especially in Holland and the United Kingdom. Liverpool and London have the longest and largest experience, but Glasgow, Manchester, Birmingham, Amsterdam, Rotterdam and The Hague all have much to teach us.
Whether it pays or not, in the larger sense, depends on the extent to which the displaced tenants are gotten into the new houses. Where they are scattered and lost track of, the advantage is doubtful. One locality has been improved at the expense of others. The technique of retaining old tenants in new houses has improved much since 1900. Under present-day methods, only a small part of a clearance scheme is torn down at once. The tenants are moved, without expense to them, into temporary quarters owned by the city, which are popularly known in England as "decanting stations," whence they are moved back when the new houses are ready. In Holland, especially at Amsterdam and The Hague, a definite educational use is made of the interval.