INTRODUCTION

Promoting the building materials sector in developing countries has been a subject of importance to the United Nations as far back as Habitat: United Nations Conference on Human Settlements, held at Vancouver in 1976. The subject has been given considerable attention in the activities of UNCHS (Habitat) since its inception, and, in recent times, it has been repeatedly highlighted as one of the most pressing areas of concern in human settlements development. For instance, in March 1985, UNCHS (Habitat) and the United Nations Industrial Development Organization (UNIDO) jointly organized the First Consultation on the Building Materials Industry,^1/ for the purpose of fostering collaboration between industrialized and developing countries, thus leading to improvements in the building materials sector in developing countries.

^1/ First Consultation on the Building Materials Industry, Athens, 26-30 March 1985.

The main reason building materials continue to receive priority attention is that they are the main input in the construction of houses, schools, factories, airports, roads, water supply facilities, dams and, indeed, the whole multitude of items which absorb the main investments in human settlements. However, building materials have been a cause of inadequate construction output, high construction cost, abandonment of construction projects and, sometimes, inadequate building maintenance in developing countries. This situation has come about because, in most cases, basic building materials are obtained from predominantly imported sources using scarce foreign exchange, so that costs are prohibitive and supply is limited.

To a large extent, the trend of rising costs and falling supplies of materials can be reversed, if the system of production is based on locally available resources. Indigenous building materials exist but are either unpopular because of their low quality or simply insufficient in supply. In most countries, efforts are being made to promote the use of indigenous building materials, and these have led, on the one hand, to improved traditional materials and, on the other, development of relatively innovative materials. However, despite the potential for their wide application in developing countries and despite increased efforts to promote their production, most indigenous building materials have not made tangible impacts on the construction market. The purpose of this report is to assess the importance of the indigenous building materials sector in developing countries and to outline the constraints which limit the wide-scale adoption of indigenous building materials and to indicate some possible measures that decision-makers and related professionals can take to resolve the issue.

What constitutes an indigenous building material will vary from one country to the next, but the basic criteria will be applicable to most countries. For this reason, this report deals with the production and use of indigenous building materials on the basis of commonly accepted principles and concepts, rather than by relevance to a comprehensive range of specific materials. However, a few building materials have been selected to illustrate the broad issues related to the promotion of indigenous building materials. The examples are limited to low-cost cementitious materials.

The report is made up of five chapters. Chapter I presents an overview of the building materials situation in developing countries, reviewing the importance to national development of the construction sector and the main obstacles to improving its efficiency. Chapter II addresses the question of what constitutes an indigenous building material, with a view to determining criteria which will be applicable to most developing economies. Constraints which limit the adoption of indigenous building materials are discussed in chapter III, while chapter IV suggests measures to promote the wide-scale adoption of indigenous building materials. Finally, chapter V describes pertinent aspects of the production and use of indigenous building materials, using selected materials as an illustration.

A review of production of indigenous cementitious materials in selected countries is provided in annex I. Incidentally, these selected materials, if successfully promoted, are likely to lead to improvements in the building materials situation of the low-income population because the factor inputs for their production are widely available at affordable costs and, moreover, they can satisfy the bulk of the requirements for low-income shelter.