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close this bookJournal of the Network of African Countries on Local Building Materials and Technologies - Volume 3, Number 3 (HABITAT, 1995, 42 p.)
View the document(introduction...)
View the documentThe Aim of the Network and Its Journal
View the documentForeword
View the documentImportance of Appropriate Building Codes and Regulations in Improving Low-Income Settlements Conditions in African Region*
View the documentKenya: Building Standards and Planning Regulations - The Kenyan Experience**
View the documentTanzania: Sustainability of Building Materials Supply in Dar es Salaam***
View the documentEvents
View the documentPublications Review
View the documentBack Cover

Publications Review

Published by UNCHS (Habitat)

Development of National Technological Capacity for Environmentally-Sound Construction

As a major consumer of natural resources and a potential polluter of the environment, the construction industry has recently come under the close scrutiny of the international community. With increasing urbanization, developing countries are experiencing a rapid change from the traditional use of low-energy, renewable building materials such as earth, stone and timber to energy-intensive building materials like cement, steel and glass. The indiscriminate use of non-renewable tropical hardwood is depleting tropical rain forests, yet there is much hesitation in the construction sector to switching to renewable species, even through cost-effective techniques for the preservation of such timber are now widely-available. Techniques for recycling of used materials and wastes have been developed but are yet to find widespread use in developing countries. The excessive use of non-renewable resources not only increases production costs but it is also an important cause of environmental degradation. The reversal of current trends will call for an effective strategy that promotes energy-efficient and low-polluting construction technologies, recycling and reuse of wastes and the use of low-energy materials.

Reconciling the seemingly conflicting goals of rapidly expanding the capacity of the construction sector to meet rising demand with those of conserving the natural resource base and controlling environmental polluting will not be easy. This will demand the ingenuity and the resourcefulness of the industry, governments and the international community. Industrialized countries have already made significant advances in this area through research, standardization and legislation. The impact of such initiatives will soon be felt in developing countries through more stringent conditionalities for development assistance, especially for more environment-friendly construction practices.

Agenda 21, adopted by the United Nations Conference on Environment and Development (UNCED) held in Rio de Janeiro. Brazil, in June 1992, has underscored the direct relationship between sustainable human settlements development and sustainable construction industry activities by including “Promoting sustainable construction industry activities” as a distinct programme area in its recommendations on “Promoting sustainable human settlement” (chapter 7 of agenda 21).

This publication represents an important milestone and the first significant step of the United Nations Centre for Human Settlements (Habitat) towards implementing the recommendations of Agenda 21 for the construction sector. This publication is targeted to policy - and decision-makers as well as professionals who, in one way or another, are involved in the construction sector, especially those in developing countries.


91 pp., HS/293/93E; ISBN 92-1-131214-0

Vertical-Shaft Limekiln Technology

Traditionally, lime was extensively used in all types of construction for centuries until the advent of Portland cement. Despite its higher price, Portland cement has become an ubiquitous material, mainly because of its high strength, consistent quality and easy workability, so much so that Portland cement is used today in low-strength applications for foundation concrete, plasters, mortars and soil stabilization - applications where lime is ideally suited. On the other hand, the acceptability of lime in the construction market has suffered owing to its variable, and often unreliable, quality, especially when it is produced in small clamp-type kilns with little process control.

There are many reasons why small-scale producers of lime have failed to upgrade their productions process to ensure a better quality of lime. First, given the severely limited technical, financial and managerial capacity of small entrepreneurs in the building-materials industry, it is too much to expect them to seek out, evaluate and acquire new technologies from the domestic and international markets. Secondly, the information generally available on improving lime production technologies is not adequate enough to make a proper techno-economic feasibility study even when capacity of such an assessment is available to the industry.

The purpose of this publication is to bridge this gap by bringing together a range of information on lime production and illustrating different technological features of small-scale lime-production processes. In view of inherent advantages and successful experiences of using vertical-shaft lime-kiln technology of plant capacities ranging from 3 to 10 tons per day, special attention has been given to this technology. An important feature of this publication is the illustration of a methodology for conducting pre-feasibility studies and for the preparation of cost-benefit analysis. Our experience has shown that many small-scale entrepreneurs who have not been able to conduct a sound feasibility study prior to setting up a plant have failed to produce good-quality lime in a competitive market. It is, therefore, hoped that this publication will provide guidance and could serve as a useful reference for those small-scale enterprises which intend to set up new lime-producing units or wish to improve the productivity of their existing units.

Readers are invited also to refer to a recent UNCHS (Habitat) publication entitled Endogenous Capacity-building for the Production of Binding Materials in Construction Industry-Selected case studies, HS/292/93E. This publication is a compilation of a number of case studies from different countries on the production and use of lime and other binding materials.


82 pp., HS/303/93E, ISBN 92-1-131225-6.

Urbanization and sustainable development in the third world: an unrecognized global issue.

The twentieth century has been the century of the urban transition, the last phase of which is taking place in the developing countries. The magnitude of this transformation of the developing world - the sheer number of people involved - is without precedent in history. However, only now, after three decades of rapid urban growth in the developing countries, is the international community beginning to come to terms with the social and economic development policy implications of this transition.

With the urban population of the developing countries set to increase by almost 800 million people between 1985 and the end of this century, it is time to abandon the notions that urbanization in the developing countries is undesirable, avoidable or even, reversible. Such beliefs tend only to contribute to policy paralysis when it comes to the urban sector. Given the number of people involved, it should finally be accepted that the urban transition represents a profound economic transformation produced by the processes of modernization and development, of which the recent dramatic demographic shifts are only the mere surface manifestations. In 1950, less than 300 million people lived in towns and cities in the developing countries. By 1985, this number had increased to 1.1 billion. Currently increasing at a rate of 50 million a year, the urban population of the developing countries will reach almost 2 billion a little more than a decade from now. This means that, by the year 2000, two-thirds of the world's urban population will be living in the developing countries of Africa, Asia, Latin America, the Caribbean and Oceanic. Decision-makers and experts should be prepared for this.

That these trends are irreversible is confirmed by any examination of the evidence. Contrary to much popular belief, the growth of urbanization and city population cannot be explained only in terms of migration from rural to urban areas. The image of cities swamped by rural migrants is undeniably a powerful one but it constitutes an inadequate basis for explaining what is happening. Only in minority of developing regions is migration the dominant element of urban growth. For the developing countries as a whole, as early as the 1960s, natural increase accounted for about 60 per cent of the growth of urban areas, and this percentage has been increasing ever since.

Yet there has not been a corresponding shift in international assistance and in national development priorities favouring the urban sector. Here, the fault does not lie entirely with policy-makers: other factors also come into play. Generations of anti-urban writers have portrayed the city as impersonal, evil by nature and conducive to social disorganization. Much has also been made on an alleged urban bias in development policies and the concept of the parasitic city, ignoring the fact that in many if not most developing countries, cities and towns are the main contributors to national, provincial and local tax revenues, in many cases outstripping rural areas not only on per capita basis but often also in absolute terms.

Nevertheless, the negative image of the city persists and has exercised the powerful influence on those who must make decisions in regard to development priorities, particularly in the donor countries. The urbanite is characterized as lonely in the midst of crowds - an individual forced to accept both the rapid pace of city life and the slow rate at which urban institutions respond to his or her needs. By contrast, the country-side retains the romantic glow of a lost Eden.

This publication addresses issues such as: The indoor, neighbourhood and city environment; Regional impact and rural-urban interactions; Environmental health problems; Urban pollution; and Global concern.


78 pp., HS/177/89E, ISBN-92-1-131099-7

The management of human settlements: The municipal level

In the “World of Cities” in which future generations will live, development prospects will largely rest on the ability of urban areas, large or small, municipal or metropolitan in character, to satisfy the following development goals: improving the living and working conditions of the whole population, and in particular, of those who are in a weaker position to articulate their needs and safeguard their rights and interest; promoting sustainable social and economic development; and enhancing and protecting the physical environment.

This challenge is of unprecedented dimensions and urgency, and meeting it will require a radically new look at the role of cities in national and global development. Central governments will have to accelerate action in the area of resource allocation, municipal reform, decentralization and empowerment of local governments if they want to enhance the contribution of cities to national development. The international community will have to redefine and strengthen its presence in urban sector. These will largely be supporting and facilitating role since both international and national resources to support local action will remain limited. The new paradigms for urban revitalization and rebirth will come from the cities themselves, and will be inspired by the diffusion and wide application of new approaches to local development emerging from the cities themselves.

The model to bring about this transition is a new, broader concept of municipal management, based on enabling principles already affirmed in the “New Agenda for Human Settlements” and reaffirmed in the Global Strategy for Shelter to the Year 2000 as well as in “Agenda 21”. This model is based on the full participation of all actors and groups contributing to the growth and development of cities in all phases of municipal management illustrated in this report: the formulation of municipal policy; the adoption of a broad-based strategic approach to the formulation of policy objectives; the formulation, implementation monitoring and evaluation of municipal programmes and plans to achieve these objectives; the enhancement of human, financial, physical and environmental resources; the improvements of municipal performance; and the establishment of sustainable and productive partnerships within the municipality, between municipalities, and at the national and international levels. It is only through these enabling arrangements that the general principles of good management - transparency, accountability, and efficiency - can be made to flourish and management environments created in which people are at the same time the determinants, the beneficiaries and the agents of improvements and change.

This publication covers topics such as: reshaping the policy environment; translating opportunity into action; key areas for improved municipal management and institutional partnership.


120 pp., HS/307/93E, ISBN 92-1-131229-9.

Co-operative housing: Experiences on mutual self-help

The Global Strategy for Shelter to the year 2000, which was adopted by the United Nations General Assembly in 1988, lays considerable emphasis on “enabling” strategies to meet shelter needs. The Strategy recognizes that governments are unable to provide shelter for the majority of their populations but that they play an important role in providing a framework which enables the private and community sectors to provide housing.

The Strategy states that

“.... Implementation of a shelter strategy will involve the redefinition and redistribution of responsibilities to a variety of actors ranging from individual households through co-operative groups and informal and formal private producers to governmental agencies and ministries”

This publication focuses on “Co-operative groups” and the role that they play in the shelter sector. It presents four experiences of co-operative groups: Two in Africa and one each in Asia and Latin America. The case studies demonstrate the advantages and problems of different approaches to co-operative housing. The four experiences encompass a wide rage of self-help solutions of housing and describe a number of institutional forms, management approaches and financial arrangements. While each country has its own particular context which influences the nature of co-operative housing, there are features of co-operative housing organizations that are common to many countries.

This publication is intended for organizers of potential co-operatives as well as for those who are able to provide support to co-operatives, be it legal, financial or technical or in other ways. It is also meant for governments which are considering policies and strategies which will meet housing needs in times of severe financial constraint and for those in government who implement such policies and strategies.

As co-operative housing programmes and projects are initiated, they will require specially developed or adapted manuals, and training materials. There is no substitute for materials which are specific to each country and even to particular cities or regions.

These are best developed using a participatory method, perhaps with the help of a facilitator experienced in training methods and materials. This publication is not a substitute for the development of specific national materials. It is a means to learn from experience and raise issues for discussion.

At the international level there are a number of publications which deal with housing co-operatives in developing countries which are identified in the bibliography in this volume. They include manuals and prescriptions for undertaking co-operative housing projects and programmes. In addition to the references included here, a more extensive annotated bibliography on co-operative housing is being published as a companion to this volume.


163 pp., HS/179/89E, ISBN 92-1-131101-2.

Case studies of innovative housing finance institutions

Lack of access to suitable forms of credit has always been a major impediment to the provision of shelter for low-income groups. While most countries have established specialized housing-finance institutions, very few such institutions have succeeded in mobilizing saving on broad base. Relying on budget allocations and institutional investor for financial resources, these institutions lend, frequently at subsidized rates, mainly to high-income and middle-income households while the low-income groups - the vast majority of urban households - have limited access to formal housing finance.

In many developing countries, government budgets are no longer a reliable source of housing finance as a result of worsening economic conditions. Moreover, heavy inflation, often triggered by the liberalization of the economy has frequently decreased private investments in housing as investors have chosen to save in the form of stocks. As a result, the low-income groups have been increasingly excluded from formal housing finance.

During the past decade, several finance institutions have developed innovative mechanisms with a view to increasing mobilization of housing finance and improving access to finance to the poor. In continuance of the UNCHS (Habitat) programme on the development of housing-finance systems, this report employs three case studies to examine the main issues in the provision of housing finance in three African countries, Botswana, Kenya and Zimbabwe. The objective of this publication is to highlight some success and difficulties and to identify key areas for attention, and not necessarily to present replicable models for housing-finance institutions for low-income groups.


79 pp., HS/301/93E, ISBN 92-1-131222-2