the nhds could be revised to include informal settlement and upgrading of existing housing stocks both in its objectives and subsequent implementation measures furthermore overall housing objectives could be reoriented to focus not only on the quantitative targets but also on the provision of adequate and accessible housing although wide spread slums do not exist in viet nam there is reference to vertical slums which are multifloor buildings which are divided into small living spaces and rented to the low income market given the financial constraint in the public sector incremental upgrading and maintenance of the existing housing stock by individuals could be encouraged