The deficit is greatest in lower- and middle-income housing, as it has been largely left to the private sector which naturally concentrates on the more lucrative higher-income segment of the market.
Historically, governments across the emerging nations have struggled to find adequate financial resources for the provision of affordable social housing and associated infrastructure, especially over the last 3 decades, to cope with population growth from rapid urbanisation and natural population growth. This has been compounded by a lack of proper urban planning.
Relatively low incomes, costly finance, expensive, unsustainable construction materials and methods (typically single-skin concrete block construction) and cumbersome regulatory and land tenure arrangements, have prevented many households from accessing basic, affordable, formal housing.
Other factors such as lack of technical skills, the absence of streamlined building regulation frameworks, approval processes and availability of good quality materials and products, have contributed further to the problem.