The Bill distinguishes between three classes of slums— (1)' elearanee
areasareas so bad that the only remedy is' demolition ; (2)' improvement areas—areas where the Conditioni can be remedied without demolition ; (3) individual insanitary houses. The local authority may require the owners of a " clearance area " them- selves to demolish the buildings. This is the cheapest method because the simplest, but the local authority will be enabled itself to buy the area, if necessary, and to arrange for the demolition. The principle of first giving the owners the opportunity of acting is new. Owners who clear , the site themselves will have the right to dispose of it, or to rebuild subject to the hical by-laws or to any existing town-planning scheme.